Classifications of Snakes and Reptiles

Classifications of Snakes and Reptiles Reptiles are some of the oldest living creatures on the planet and made their first appearance some 300 million years ago. It is believed that the first species of snakes contained limbs which became more and more reduced through great periods of time, this phenomenon can be seen as a clear indicator just how evolution took place within a group of organisms. Today vestigial structures occur in certain serpent families such as Pythonidae and Boidae, and are remnants of structures they once possessed. Spurs which occur in the posterior position opposite the cloacae in Boas and Pythons is a clear example of vestigial structures that formed through time. Snakes are carnivorous reptiles that belong to the order Squamata (Lepidosuaria), which is regarded the most important assemblage, as far as snakes are concerned. Squamates is a very diverse group of ectothermic (organisms that rely on their external environment to obtain the energy needed to facilitate metabolic and other processes crucial for life), amniote vertebrates which contain the distinct characteristic of being elongated and covered in overlapping scales. Squamata is subdivided into three distinct suborders: Ophidia or Serpentes, containing snakes, Sauria containing lizards and Amphisbaenia containing worm- lizards. The suborder Ophidia contains 15 families which are subdivided into 456 genera that consist of more than 2900 species. Snakes have one of the widest distributional ranges in the animal kingdom, covering the whole planet except Antarctica (Figure 1.1). In South Africa alone there occurs 166 species and subspecies of snakes, 101 of these species have enlarged fangs to deliver venom of which only 15 are regarded as very dangerous and potentially fatal to man. This means that of all our snake species only 8.5% are classified as dangerous, where administration of antivenin is deemed necessary. The remainder of venomous species is of no medical importance to man, in fact in some species the toxicity of their venom is less than that found in bees and wasps. There are a few morphological characteristics of Ophidia which distinguishes them from the other two suborders e.g. the lack of eyelids, external ears, the lack of limbs and the occurrence of a single row of ventral scales, whereas lizards and amphisbaenas differ in the sense that they have various patterns of scales that do not occur in specific rows. Amphisbaenians scale formation is atypical in the sense that scales are arranged in rows around the body of the animal thus supposedly mimicking the resemblance of an earthworm. The skulls of Serpents are very unique in the sense that their upper jaw bones arent united/interconnected at snout of the animal, this enables the two jaw bones to act separate form one another and enables the snake to swallow large prey items. In contrary to popular belief snakes can however not dislocate or unhinge their jaws to swallow large prey items, the two upper jaws are simply connected to each other through connective tissue which is highly elastic a nd serves as the binding factor between the jaws. Snakes fulfill a crucial role/function in nature and can be seen as an integral aspect of our environment both as key predators and as prey. They assist in regulating rodent numbers and are good indicators of the natural balance of the environment (bio-indicators). In addition to this, research and development is being done on the properties of venom in the medical field. Research is being conducted on the applications of venom in fields such as high blood pressure, mental disorders and diseases of the central nervous system to mention but a few. Such is the complexity of venom that further studies, beneficial to man, are essential. It is there for imperative that we conserve our snakes not only for the preservation of our environment, but also for the wellbeing of mankind. Evolution that took place within the Class Reptilia Reptiles evolved from prehistoric amphibians called Labrynthodonts (Flank, 1997), and according to paleontologists made their first appearance in the Pennsylvanian era some 300 million years ago. They were also the first vertebrates to escape dependency on water. The earliest forms of reptiles suggested a mixture of both amphibian and reptilian characteristics, and diversified greatly over the next 200 million years. Reptiles were the dominant animal group on earth during the Mesozoic period, and were represented by 15 major groups. Only 4 of these orders survive today. Extinct are the fishlike Ichtyosaurus, sail-backed Pelycosaurs, flying Pterosaurs, Mosasaurs, plesiosaurs, well-known dinosaurs like Brachiosaurs and many others. The dinosaurs included the largest animals ever to walk on earth-the Sauropods, some of them reaching lengths of nearly 27 meters long. Many of the less familiar dinosaurs were no longer than chickens. (Carr,1963) Several basic advances made possible the rise and wide distribution of reptiles on land. Most important was the amniote egg, with its tough outer covering and protective membranes, and a cornified skin that protected the animals from drying out. The positioning of the limbs also made it possible for reptiles to move more easily on land, and an improved circulatory system ensured that oxygen rich blood reached the animals. In their Mesozoic heyday, Reptiles dominated the land, seas and air, and the reason for their dramatic decline during this period is still not clear, although there are some speculation by biologists that the decline was probably caused by a meteor shower which altered a dramatic change in climate and giving rise to the so called Ice Age. Warm blooded vertebrates (Birds and Mammals) began to expand by the end of the Mesozoic period. By the time the Cenozoic period arose only 4 orders of reptiles still existed, and these same four have persisted to this day. The order Rhynchocephalia is represented by only one species, the lizzardlike, granular scaled Tuatara (Sphenodon punctatus) confined to New Zealand where its survival is now threatened. The remaining 3 orders have representatives throughout the world. The order Testudines (turtles) is the most ancient, appearing about 250 million years ago and remaining virtually unchanged for the past 200 million years. The order Crocodylia (cro codilians) is slightly less ancient and is traceable to the Permian thecodonts. The order Squamata refers to scaled reptiles that include lizards, amphisbaenids and snakes. This is the most recent order and was not common until the late Cretaceous times about 65 million years ago. In order to classify snakes or other organisms it is necessary to understand the origin and evolution of the species and place them into specific genera and families (Figure 1.2) Scientists believe that modern day snakes evolved from the family Varanidae, a group of lizards that belong to the genus Veranus. The fossils of Lapparentophis defrennei (Figure 1.3) was found in North Africa as we know it today, and it represents the earliest member of the suborder Ophidia. This species however shows no direct link between earlier snake like reptiles, and its origin continues to boggle biologists. Lapparentophis defrennei appeared on the earth around 100 million years ago during the Cretaceous period and were around for about 35 million years, were after it got extinct by the end of the Cretaceous period. Boidae was one of the seven families of snakes that arose after the Cretaceous period and was at its peak of speciation during this time. Colubridae in modern day times is the family that contains the largest amount of different snake species, and first emerged some 36 million years ago during the late Eocene, and the beginning of the Oligocene period. During this time Colubrids started to diversify at an immense rate and eventually gave rise to more new species during the Miocene period. This diversification led to the disappearance of some of the more primitive lineages of snakes because they could no longer compete with the better adapted species that was starting to evolve. Viperidae (vipers, rattle snakes and adders) and Elapidae (front fixed fang snakes generally cobras and mambas and their relatives) originated during the Miocene period and belongs to the infraorder Alethinophidia. The family Viperidae is by far the most advanced evolved species of snake in the world and contains highly specialized structures that enable them to be a very successful hunters e.g. heat- sensitive pits that developed on the upper labial and a brightly colored tail tip that occur in Agkistrodon sp. This is just one example of how specialized this family of serpents is to survive. Distinguising features of the suborder Ophidia All snakes are elongated, lack eyelids, external ears and osteoderms. Snakes poses a forked tongue which can be retracted into a sheath (Figure 2.1) All have along backbone. (Some have in excess of 400 vertebrae), with many articulated ribs used predominantly for locomotion and maintaining body shape. The lower jaw is not fused, which allows the snake to engulf large items. They do however not dislocate their jaw. Prey is subdued either by constriction or by the injection of venom. In the case of venomous snakes small prey items are bitten and held in the mouth until paralysis or death occurs, whereas large prey items are bitten and released to ensure that damage do not occur to the snake. The majority of species have only the right lung but more primitive species such as Pythonidae and Boidae also contains a rudimentary left lung. Unlike lizards the tail cannot be regenerated. All snakes shed their skin. All snakes hatch from eggs, some are Oviparous (eggs hatch outside the females body), and some are ovoviviparous (eggs hatch inside the mothers body thus giving birth to live young). Classification of snakes Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Reptilia Order: Squamata Suborder: Ophidia (Serpentes) Infraorders: -Alethinophidia -Scolecophidia The classification of snakes are based on different morphological structures The general morphology of snakes is a crucial factor used in their Taxonomy. Factors such as the arrangement of bones in the skull and other parts of the skeleton, especially the presence or absence of a pelvic girdle are used to distinguish between separate and subspecies of snakes. The hypapohyses (vertebrae with downward pointing spike like projections), the coronoid bone (a small bone that occur in the lower jaw), structures of the hemipenes (Figure 2.2, Jadin, 2000) and microscopic and biochemical material such as chromosome arrangement and protein analyses are also used in classification of snakes. The presence or absence hypapohyses, especially in the lumbar region of the spine, is used as one of many diagnostic characters when classifying snakes. The hypapohyses is very prominent in the genus Dasypeltis which use them too saw trough egg shells. There occurs much variation in the shape and size of the coronoid bone. It is particularly large in primitive snakes such as Typhlopidae, Leptotyphlopidae and Anomalepididae. The coronoid bone is very small or absent altogether in advanced snake species. A hemipenis is the sex organ of male Squamates. Male snakes has two hemipenes probably for the reason that when one is damaged or injured, it still left with a spare one which can remain to work and carry out its normal function during copulation. This ensures that the males genes dont get lost and can still be carried over through copulation with females. Hemipenes, under normal conditions are used in an alternating fashion when copulation occurs with female individuals. Sperm is carr ied through the sulcus spermaticus (which is the line running through the middle of a males hmipenis) to the female during copulation. By examining the tail of an individual we are able to distinguish its sex. Males usually have a long tail which contains prominent bulges of where the hemipenes are situated and females usually have very short tails without the occurrence of any prominent bulges. The shapes of hemipenes differ greatly from species to species and contain different cranial structures thus forming a very important method for taxonomists to classify snakes into different species and subspecies. Relationships that occur between different species of Squamates as a result of evolution is best explained through the examination hemipenal characteristics of the different species. The function of the spines and ridges that occurs on hemipenes of different species of male snakes, serves as an adaption to ensure that copulation lasts long enough for egg fertilization to occur. Biology Hearing and Vision Snakes cannot hear airborne sounds due to the fact that they do not posses external ears. Snakes do however have an auditory nerve enabling them to hear sounds travelling through a dense medium. They are extremely sensitive to vibrations and can thus detect someone or something approaching them. For this reason people seldom see snakes whilst walking in the bush, the snake senses the vibrations created by footsteps and beats a hasty retreat for cover. There is however snakes that do not retreat when approached and this is a direct result of the morphological attributes they contain. Bitis arietans, Bitis atropos and, Bitis gabonica, are species of snakes that rather rely on their camouflage to conceal them from potential predators and dangers than to move away, and it is not surprising to find out that Bitis arietans is responsible for 60% of all snake bites in Southern Africa. Contrary to popular believe snakes do have good vision. How else would they safely navigate through the bus h except of course via smell? Their vision however is used mainly for detecting movement. Most snakes have monocular vision (unable to distinguish depth of field) whilst some snakes have binocular vision (able to distinguish depth of field) e.g. Thelotornis capensis and Dispholidus typus. Snakes do not have movable eyelids, instead they possess a fixed transparent shield which covers the eye and is shed during sloughing. Sense of smell For this function the snake uses its tongue. The tongue is flickered; picking up minute airborne particles which when retracted back into the mouth is deposited onto organs situated in the roof of the mouth. These organs are known as the organs of Jacobson. Studies have shown that snakes enjoys a similar sense of smell as we do, the epithelium of the organs of Jacobson works in exactly the same way as the olfactory epithelium we as humans possess. The tongue is forked so that the snake can detect the differences in strength of smell and thus enabling it to locate its prey very accurately. Snakes diet consists of quite a few prey items such as: rats, mice, small mammals, birds, frogs, toads, insects, lizards, fish, small antelope, eggs and other snakes, which is swallowed whole usually head first. Shedding Shedding of skin depends primarily on the growth rate. Juveniles for example shed their skin more often than adults for the simple reason that they are growing faster. Juveniles may shed their skin as often as twelve times a year whereas an adult may only shed its skin three to four times a year. During this process the entire skin is shed from the tip of the snout through to the tail including the eye shields. During this time the snakes eyes become opaque, restricting the snakes vision and therefore making the snake not only more vulnerable, but also more aggressive. A snake may often go into hiding during this period. You may also find snakes basking for longer periods prior to shedding, the reason being higher temperature speeds up the development of new skin, thus reducing the vulnerability period. Cold Blooded (Ectothermic) and Hibernation All members of the order Squamata are so called cold blooded (exothermic) organisms. This simply means that unlike mammals and birds which generate heat internally (endothermic), reptiles obtain their heat externally, usually from the sun. All reptiles will bask in the sun absorbing heat from their environment until their bodies reach the correct optimal temperature (ÂÂ ± 30Â °C) which allows them to function at their maximum potential. The advantage of ectothermy is that it is fuel efficient. Mammals on the other hand convert 90% of what they eat into heat in order to maintain biochemical and muscle efficiency which allows mammals the opportunity to function at colder temperatures. This method demands a constant intake of food. Reptiles however become temporarily dormant at colder temperatures and thus waste no energy. A snake can survive and grow on ten to fifteen meals a year. Reptiles will go into hibernation when their optimal body temperature cannot be achieved from the e nvironment. In areas where there is a significant fluctuation in temperature snakes will go into hibernation. The correct term used is topor. Areas such as the lowveld where there is no significant temperature variations will see reptiles not going into true hibernation but rather into a state of burmation. During hibernation snakes live off the body fat accumulated during the warm periods of the summer, and will exhibit very little signs of activity, thus becoming sluggish. A snake will use anything that will offer it protection against the elements and predation. Sites which are used by Squamates during the winter or cold times of the year for hibernation include deserted termite mounds, hollow logs and rock crevices. Reproduction Sexually active males will approach any snake they come across. The reaction of the approached snake will determine how the encounter develops. If the approached snake is a male and reacts aggressively it may give rise to a battle between the two parties. Battles vary according to species, Vipers and Elapids generally engage in a form of ritualistic wrestling, but refrain themselves from biting each other. Colubrids however react violently and bite each other severely. In some species of snakes several males group together amicably and follow a receptive female. Should there be no reaction from the approached snake the sexually active male uses its Vermonasal organ to chemically determine the species and sex of the snake it has approached. It does so with the use of its tongue interpreting the pheromones emitting from the other snake. Should it be of a different species, the male then seeks out a new mate. All reptiles have internal fertilization. The male places his head on the back of the female and winds his tail around the females and attempts to join their cloacas together. This is seldom achieved at the first attempt. It sometimes takes hours, even days, for successful copulation to take place. The sexual organs of the male consist of two penises, referred to as the hemipenes. Each hemipene is equipped with flexible spines which inflate once penetration has occurred making it difficult for the male and female snakes to become dislodged. Sperm is transferred to the female via a single penis in Crocodilians and Chelonians, and paired penises in lizards and snakes (although only one penis is used at a time). Once mating has taken place the male will often stay with the female for a few days to mate again. Fertilization of the ovule and spermatozoid takes place high in the oviduct, then the egg gradually moves down into the oviduct where the uterine glands secrete a substance which surrounds the egg. The length of the embryonic development depends on the species and also within the species depending on climate (temperature), and ranges from 2-5 months. As stated before all snakes hatch from eggs. The method of incubation however does differ between some species. The majority of snakes lay eggs andleave them to be incubated externally (oviviparous) with no parental care whatsoever. Species such as Python natalensis coils around their eggs throughout incubation. This not only protects the eggs but also regulates the temperature to help assist with incubation. In other species such as Hemachatus haemachatus the female retains the eggs inside her body to produce fully developed live young (viviparous). Between four to eight weeks after mating the female selects a suitable site to deposit her eggs. The site chosen is usually a suitably protected place in the form of rotting vegetation, hollow tree trunks or any other suitable location. The number of eggs deposited depends on a variety of circumstances for example, species, size of the female, habitat (availability of food), age and climate. Eggs laid vary between one and two to as many as 60, sometimes more, depending on factors mentioned above. Eggs usually have soft leathery shells which require a specific amount of heat and humidity in order to ensure that hatch. Once the eggs have been laid there is often no parental care with the exception of a few species. In South Africa the young of Python natalensis may stay with the female for several days after hatching, leaving the burrow by day and returning to the female at night. In most reptiles the sex of hatchlings is determined by temperature, for example outer eggs (cooler) will be female while the inner eggs (warmer) within the nest will be male. The eggs usually hatch between one to three months after the female has deposited them. In the case of some species of chameleons eggs might take up to a year to hatch. The young are equipped with an egg tooth consisting of a sharp ridge on the tip of the snout which allows the young to slit open the eggshell thus freeing itself. The young that emerges are exact replicas of the adults, and the hatchlings of venomous snakes are equipped with fully functional venom glands and fangs, and are thus venomous directly from birth. Egg mortality is quite high. Reasons for egg mortality range from predation to unsuitable nest sites chosen. Giving birth to live young may be an evolutionary process to assure the success of a species, reducing the risk of egg mortality in particularly cold areas where the temperatures wont be adequate enough for incubation. Movement (Locomotion Speed) The ability to function at speed and endurance is directly related to the supply and amount of oxygenated blood to the body. Reptiles, unlike mammals and birds, do not receive as good supply of oxygenated blood. Directly translated, this means that reptiles tire more easily and are incapable of endurance. Based on these facts it is doubtful that the speed of a snake would exceed 20km/h which is much slower than the average human. The two fastest snake species world occur in Southern Africa and belongs to the genus Psammophis and Dendroaspis. There are four basic modes of locomotion in snakes: Sepentine This is the more familiar method of locomotion that most snakes use e.g. the family Elapidae which makes use of this method. The body undulates from side to side while the hind part of the snake makes contact with the surface and the rest of the body is pushed in the direction the snake wishes to go. Caterpillar These are usually heavy bodied snakes e.g. Bitis arietans. The snake progresses in a primarily straight line using its ventral scales to propel it forward. Concertina This is when a part of the body is anchored whilst pushing forward. The snake may anchor its head and then drags the rest of the body towards the head. This is often seen in arboreal species when negotiating between smooth braches of trees. Snakes that make use of this type of locomotion usually contain the characteristic of keeled ventral scales, and include species of the genus Philothamnus. Sidewinding This method is most seen in desert species. It is the most effective method of locomotion on loose unstable surfaces such as sand. Only one or two sections of the body are in contact with the surface at any given time. A section of the body is thrown sideways and is followed by the next section. This way of locomotion can be seen as a specific adaption for desert species e.g. Bitis peringueyi, to ensure that they dont get burned by the hot desert sand when moving. Scales Most people refer to snakes as being wet or slimy, which is quite the contrary. In fact if you touch a snake you will notice that it is in fact dry. Scales are horny skin that originates from the snakes epidermis. The primary function of scales is to prevent rapid water loss, an evolutionary process which has allowed snakes to move onto land. Scales can be smooth or keeled. Some snakes use their scales as a warning mechanism. By rubbing them together this creates a rasping sound that serves as a warning to would be predators. Dasypeltis scabra is a species of snake that occur in Southern Africa and which use this specific defensive mechanism to ward of predators. The North American rattlesnakes rattle is also an example of modified scales that formed through evolution. Scales also help in the locomotion of snakes. Scale counts remain one of the main methods in the identification and classification between different species of snakes. There are four methods which can be used to correctly identify a species via scale counts: Head scales This is done by counting the upper and lower labials on each side, taking note of which scales are in contact with the eye. Examine the nasal scales (single, semi-divided or fully divided). Count the number of preocular and postocular scales and check whether a loreal shield is present. There should also be taken note of the arrangements of scales that occur on the temples, and the presence of any fused scales. Observe the relative sizes of internasals, prefrontals, frontal and parietals, and also note the proportions and shape of the rostral scales at the front of the nose. Dorsal scales Note whether the scales are smooth or keeled. And one head length away from head and in front of the cloaca Subcaudal scales The first scale is the single or paired scale that meets the lateral scales on both sides. Count back along the tail towards the conical tip. Note whether scales or anal shields are single or divided as this forms a crucial part of the identification between different families of snakes. Internal Anatomy of Snakes A snakes skull is specifically designed to suit their specialized feeding habits. Because a snake cannot chew its food and must swallow it whole it is important that the snake be able to open its mouth very wide. For this reason the fifty odd bones in the skull are not fused together, instead they are loosely connected to each other by ligaments which allows the snake to produce an enlarged gape allowing it to swallow prey much larger than its head. The concept is similar to an elastic band. Often after a snake has eaten it will seem to yawn, this is done simply to relax the ligaments and bones t their original shape. The structure of a snakes brain is very similar to that of a bird, but unlike birds and mammals snakes lack the enlarged cerebral hemispheres. In mammals (and birds) the cerebral is the part of the brain, which acts as the learning center of the organism. For this reason, although snakes are perfectly adapted to the environment, it is correct to say that snakes are not very intelligent. To allow snakes to engulf such large prey whole the stomach has to be very strong and elastic allowing it to expand greatly once prey is engulfed. Powerful digestive juices allow the snake to digest bone and teeth. Because a snake is for the most part long and cylindrical, the shape of the lung must be somewhat different in order to fit inside the snakes body. The right lung is usually the largest and extends for 1/3 of snakes body length. The left lung, in most cases is absent, or very small. Snakes have in effect only one lung. During feeding the snake is able to extend a muscular extension of its windpipe (epiglottis) from the bottom of its mouth allowing it to breathe while prey is being consumed. Most reptiles have a primitive three chambered heart which is not as effective as the four chambered heart found in crocodiles (and mammals). In snakes oxygen depleted blood gets pumped into one of the top chambers while oxygenated blood gets pumped into the other top chamber, both chambers get emptied into the bottom chamber and then circulated through the body. This is the main reason why snakes tire easily. In proportion to their body size snakes have very large kidneys. The left kidney is situated behind the right kidney in the abdominal region. The function of the kidney is to filter the waste products from the bloodstream and pass them on to the cloaca for excretion. Unlike mammals which excrete nitrogen waste in the form of water soluble urea, snakes excrete these body wastes as crystals which forms a dry white paste which is excreted along with the feaces. This allows reptiles to be extremely efficient in their use of water. Mammals have a separate urinary, reproductive and a nal opening. Snakes however do not. Instead they have a common chamber known as the cloaca which performs all these rudimentary functions. Waste material is stored in the cloaca until eliminated. The claoca opens to the outside through a transverse slit at the base of the tail. It is often possible to tell the difference in sexes between species by looking at the length from the cloaca to the tip of the tail. The longer the distance between these points would signify the snake as being male whereas a short distance between these points would indicate the snake as being female. The reason behind this is that during reproduction, as mentioned earlier, the male wraps his tail around the females. Some snakes, like the Pythonidae family, have special glands which also empty into the cloaca, these glands contain a foul musky scent which can be ejected when a snake is threatened, frightened or stressed. Venom There is no easy describing venom. Simply put, snake venom is highly modified saliva which is produced by modified saliva glands. Venom is a combination of different enzymes, or proteins, that act on other chemicals and proteins thus altering them or simply breaking them down. Many of these proteins are harmless, but some are toxins. The makeup of these toxins varies widely from species to species. Snakes venom can therefore be best described as a cocktail of hundreds of different proteins and enzymes, this complexity alone accounts for widely differing effects of snakebite. In essence venom affects the protein and chemicals of the immune system and the blood, transported through the body via the lymphatic system. The venom glands are situated in the skull slightly behind the eyes. In order for venom to be effective it has to be injected into the circulatory system. It is therefore quite safe for a normal healthy person to drink venom without any consequences. Venom cannot be compared to poison, and are totally different entities. Venom has to be injected (circulatory system) Poison has to be ingested (swallowed) The functions of venom are numerous: Prevents the putrification of prey prior to ingestion. Immobilizes prey thus preventing the snake from being injured. Digestive properties within the venom begin the digestive process prior to ingestion. Snake venom is also antibacterial, antiviral, antifungal and antiprotozoal which protects the snake from microbial diseases which it may contract from prey. As a last resort, self defense when the snake is threatened. There are three types of snake venom: Neurotoxic nerve acting venom (Elapidae). Cytotoxic cel destroying venom (Viperidae.) Haemotoxic blood acting venom (Colubridae). Fangs (Dentition) All snakes have teeth, but not all snakes have fangs. Most snakes have teeth on the upper and lower

san jose :: essays research papers

sometimes in each persons life there is a turning point, a point in time when a revelation is reaveled to you. If you cannot see this revelation sometimes your vision may be clouded over by a voice that may or may not be your own. In the novel, many people are telling san jose to stop listening tom his own voice and folow them. But he knows that is wrong. At Polemarchus' house, Socrates discusses old age with Cephalus, Polemarchus' aging father. Cephalus says that old age is really not as bad as people say it is; if you're a moderate and contented person, your virtue makes old age pleasant. Socrates notes that some would say that it is Cephalus' wealth that makes old age bearable for him. Cephalus says that this is not true, wealth can help someone be virtuous, but it isn't the deciding factor. Cephalus defines just behavior as paying one's debts and speaking truthfully, and notes that wealth does help in these things. Socrates questions Cephalus' definition of just behavior, but before they can discuss it Cephalus leaves, leaving his argument to Polemarchus. Polemarchus defends his father's definition, saying that justice is giving each what is owed to him--treating friends well, and enemies badly. Socrates finds numerous problems with this definition. First is that, since people are sometimes mistaken about who their friends are, it appears to endorse treating bad people well and vice versa. Second is that, since injustice breeds injustice, it says that it is the job of the just person to create injustice. Just as Polemarchus agrees that his initial definition is incorrect, Thrasymachus, another guest at the house, roars into the conversation; he announces, with some pomp, that "justice is nothing other than the advantage of the stronger." In all cities, the rulers enact laws that are in their own best interests, and these laws are declared just, and so clearly justice is always at the service of the powerful.

Just A Pot Of Basil

At the age of eight one of my favorite things to do was dream about living in a time where gigantic beasts loomed over the earth. Form the gigantasaurus to the brontosaurus I enjoyed anything from the Precambrian period. I grew to appreciate the monstrous creatures even more after I took my first trip to the Carnegie Museum of Pittsburgh. I had never seen such elaborate displays of marvelous full-scale dinosaurs, since I was accustomed to seeing them no larger than the height of a book or television screen. I recall roaming through the many displays pretending that I was one of them. Usually, I pretended to be the Troodon, a species that is thought to have the largest brain in proportion to the rest of its body. Even though I was smaller than the rest of the dinosaurs, I always knew that I could outsmart them if I was a clever Troodon. Of course I would forget that they had been extinct for millions of years, as the plaques in front of the enormous exhibits reminded those who were tall enough to read them. But I carried on in my world of dinosaurs while I was in the museum, free to dream as I cared to. The distance and time between the real dinosaurs and I disappeared when I was in the museum, in my little world. Therein lies the significant difference between seeing and imagining, and being told or influenced, that is, being mystified. Mystification, as the art critic John Berger in Ways of Seeing explains, is the process of explaining away what might otherwise be evident (Berger 112). I was instantly captivated from the moment I saw the tied-together skeletons stretching as high as my own house; should I have cared about the petty details that would have distracted me from my own imagination? Original paintings are silent and still in a sense that information never is (Berger 125). The skeletal remains of ancient beasts strung up give only a portion of what such creatures really were millions of years ago. The color of their skin, the texture of their bodies, or even the size of their internal organs are just a few of the endless questions that remain unanswered, lost over time. But museums give something more than any book could ever tell, and that is the real life experience of seeing what could never be perceived otherwise. When life breathed through the dinosaurs they were never frozen into a perfect stance like they are portrayed in museums. Our imagination allows us to fathom what it really may have been like, but the past remains where it is, and can only at its best be relived in movies or museums or our imagination. Museums have never made me feel awkward or uneasy, they come as second nature to me. I enjoy being enveloped by a different emotion each time I look at the skeleton of a dinosaur, or see a mummified pharaoh, or even a beautiful painting of a landscape. I have always been able to let everything go, and be consumed by a striking or stunning image. The wonderful thing about museums is that every few feet there lies an artist waiting to draw you into their world. Artists and their works contained within a single building span over centuries and continents. All contain different points of view and expresses it to the best of their abilities. Today we see the art of the past as nobody saw it before. We actually perceive it in a different way (Berger 112). History meets in a museum, and constantly forms new accounts through time. Each day that passes we have gained something which may add to our overall perception of the world around us. This is why Berger claims that we see things differently and therefore there exists no definitive account of exactly the way things were at any specific moment in time. It is lost forever, and at best, can only be saved in an altered form. There is something magical about the power of the atmosphere of a museum. The silence is filled with a sea of thoughts running through viewers minds. When I first saw John White Alexander s painting Isabella and the Pot of Basil I was immediately captivated. Even my first glance told me that there was something more to the large pot in the painting than meets the eye. In a painting all its elements are there to be seen simultaneously (Berger 121). What the eye can perceive in an instant may take pages to explain. There lies the beauty of art. One glance at Alexander s work captivated me instantly. There lives some hidden secret inside the woman s soul that lay next to the pot. And sure enough, the small plaque beside the painting described a story that told me that my assumptions were correct. The painting was written as a reflection of a poem written by John Keats. Here, briefly, is the story of Isabella and the Pot of Basil. Isabella had two brothers that expected her to marry a well-endowed man so they could collect a significant dowry from her marriage. But Isabella never married, and fell in love with a carpenter named Lorenzo, who was working for brothers. The two were madly in love, and visited each other frequently whenever they were certain that no one could find them together. Soon though, a brother learned of their secret, and the two brothers took Lorenzo into the woods, killed him, and buried him in a shallow grave. One night while Isabella was wailing in bed over the mysterious disappearance of her supposed runaway love, Lorenzo’s ghost came to her and described the occurrences and location of Lorenzo s body. Isabella went to Lorenzo s grave, cut off his head, and took it back home with her where she put it in a big basil pot and covered it with moss, soil, and basil seeds. She watered the seeds with rose water and her own tears and talked to her basil until it grew incredibly lush. After her brothers stole her basil pot, Isabella died of misery and heartbreak, singing a song about the loss of her basil and love. Alexander was able to condense this entire love story into a single painting. Without having read the 500-line poem or at least having some knowledge of the story, the average viewer would never have guessed that her lover s head was contained in the pot. The emotions contained within Isabella and her sacred pot reach beyond words. The pain that she felt consumed her to the point of her own death, where no words can exist. Depicted in the painting is not just a sad woman, but a woman who is about to die, sick and miserable with heartbreak, love, and loneliness. The meaning of an image is changed according to what one seen immediately beside it or what comes immediately after it. [It] is distributed over the whole context on which it appears (Berger 123). Only after reading the small plaque beside the work and continued research after visiting completed my perception on the almost life sized piece of art. These important clues added to what I could deduce from the painting. Without them I would merely have seen just a pot of basil and a woman lying next to it. History is a mystery that is continually being investigated. Without knowing the past no deductions can be made of the present. Alexander captures Isabella in a moment of perfect stillness. Perhaps she is already dead in the artist s eyes, lying beside her love, their souls reunited. The barren space below the pot could contain the spiritual body of Lorenzo. Alexander seems to have purposefully left the open space on the right side of the painting for his spirit next to her. Isabella has her eyes closed and her hand is gingerly extended. Her two fingertips brush against the side of the pot, as if she s imagining the pot to be his face. Her neck appears slightly extended as if she were giving the curved pot a gentle kiss. The stench that must have emanated from the pot would have been almost unbearable to others, yet somehow the power of love caused Isabella to ignore all reason and sanity as her soul sought for her love and mercy. White flowers contrast with the overall melancholy of the image yet also add just the right touch of beauty, innocence, and peace. There are several of these flowers directly under the pot and another at the base of Isabella s feet. This white represents the purity of their love that was so terribly destroyed by her evil brothers. The tear of her garment on her right shoulder shows her distress and her apathy towards her self-appearance. Isabella s soul can be at ease once she is reunited with her beloved Lorenzo; her physical condition no longer matters. There are of course many other paintings depicting Isabella and the Pot of Basil, but none seemed to capture the emotion as well as Alexander does. His art is powerful, captivating, and entices the viewer to look deeper, to learn more, and to almost feel the emotions raging through the canvas. The moment I saw the painting, I knew that there was more to it. The stillness that Alexander recreates reaches beyond words, and required only the same silence in return. The way we see things is affected by what we know or what we believe When in love, the sight of the beloved has a completeness which no words and no embrace can match (Berger 106). Perhaps my heart goes out to Isabella, for I myself am in love and can reconcile with what she may have felt. Even if Isabella was just a fictional character for both Keats and Alexander the emotional consequence of such a painting is undeniable. The love between a man and a woman knows no end, and its eternity continues through people of all time and nations. Of course we are all granted different perspectives, but there lies a central burning passion about love which can only be depicted as a fraction of its entirety. Thus, love in fact, [closes] the distance between the painting of the picture and one s own looking at it (Berger 125). The research that I completed on Isabella and the Pot of Basil introduced a different and more in depth perspective on the work. Without reading the corresponding poem, I would perhaps have seen only a woman standing next to her favorite pot, and be left to imagine what more was involved. My intuition told me that there was more to the painting than what first met my eye. The observations and assumptions that I made based on the picture and poem are based completely my own deductions and learned assumptions that I have acquired throughout my life. Therefore, if John Berger had looked at this image in the same atmosphere as I did, he could have seen something completely different. Therein lies the truest beauty of art, for art is capable of capturing and recreating a moment lost in time without regard to the opinions of those who will see it. Art is beautiful often because we make it beautiful. Big ugly dinosaurs are certainly not beautiful to most, but to me as an eight-year-old, they most definitely were. Being told what is beautiful and what meaning lies behind a painting is the epitome of mystification. According to Berger this lends [undeserved] authority (121) to the artist. The image now illustrates the sentence (Berger 122). And thus, whatever thoughts a viewer has conjured about a painting or work of art are lost, negated, or skewed, yet it provides a strong basis for interpretation. The painting by Alexander exemplifies the poem by Keats. In many instances, poetry is associated with a visual image, but provides only the framework from which a perception of an image can be formulated. Words help set the tone, yet can never deter from the heart of work. I prefer to say that sentences help to illustrate an image. And John Berger would most certainly agree that there is much more to Alexander s work than just Isabella and a pot of basil.

What is the Purpose of Critical Criminology - 2011 Words

Critical criminology is a study of crime using a conflict perspective which considers the causes and contexts for crime, deviance and disorder; it has also been known as radical criminology and the new criminology. This perspective combines a wide range of concerns from across the more radical approaches, such as Marxism and feminism. It incorporates a wide number of ideas and political strands, generally associated with an oppositional position in relation to conventional criminology. Raising epistemological questions about the ideological foundations of criminology has been the objective of critical criminologists. Critical studies are extremely important in this respect as they keep us all on our toes with regard to our own†¦show more content†¦The central problem was that wholesale improvement in social conditions resulted in not a drop in crime but rather the reverse (Young 1998, p.159). Critical criminology had a significant impact on academic criminology over two decades ago but still remains important and influential today. The new criminology had a brief period of decline and is now experiencing a resurgence of interest and influence (Walton Young 1998). Critical criminologists raise a number of important questions and see crime as a process related to wider economic and political structures of power. They question the way social control operates and is used. They explain crime as a result of the alienation and powerless of the working class, con trolled by capitalism. The focus for structuralist criminology is the crimes of the powerful and the crimes of the less powerful. The ruling class was seen to create laws that served their basic interests and also to exercise a hegemonic influence over all classes in society; ruling class laws. These laws were created to serve and protect the interests of the powerful; the higher classes. Gramsci states that the ruling class maintain power by securing the consensus of the ruled. This was achieved by the maintenance of a hegemonic culture in which the ruling class power is legitimised and the ruled in effect consent to be ruled by accepting (Corall H 1998). A major work in this tradition was Hall et al Policing the Crisis in 1978.Show MoreRelated The American Society Of Criminology Essay1602 Words   |  7 PagesThe American Society Of Criminology â€Å"AHHHHhhhhh!† I let out a girlish scream and squirmed as shivers went strait up my spine. I was glued to the latest episode of CSI: Crime Scene Investigation, a show that I have watched religiously since its debut. Criminology is something that has always fascinated me, and is a career that I hope to pursue in the future as an FBI agent. I frequently surf the web looking for short stories to read about different criminal cases and to find informationRead MoreCriminology1427 Words   |  6 Pages(Siegal, 2010) (McLaughlin amp; Muncie, 2005) Criminology 211 Essay This essay topic consists of two main components. The first requires you to demonstrate your knowledge of and a familiarity with the theory/perspective and the second requires you to demonstrate an understanding of its application (in either policy or practice) and the impact of its application. i)  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Briefly identify the main features and concepts of radical criminology. ii)  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Critically discuss theRead MoreThe Role Of Criminology And The Criminal Justice System1565 Words   |  7 Pagesfound guilty are punished for their crimes. Criminological enterprise In the above context, criminology therefore refers to the scientific approach to studying criminal behavior. Apparently, every crime committed is usually motivated by different factors. For instance, some people end up committing offenses due to the inability to control their anger while others become overwhelmed by their greed. Criminology is therefore the body of knowledge regarding crime as a social phenomenon. Not only does itRead MoreThe And Tenets Of Life Course Criminology1587 Words   |  7 Pagesas one way to understand and explain this complex issue. Life-course criminology (often referred to as DLC) emerged from this perspective as a way to help explain age in relation to crime. The purpose of this proposal is to highlight the key areas of life-course criminology and outline how they reveal the value of the theory for research purposes. These key areas of interest are the genesis and tenets of life-course criminology, its key contributors and critics, and how both of the se parties haveRead MoreCriminology And The Social Theory Essay1726 Words   |  7 Pages The ideology ‘rendezvous discipline’ refers to the study being multidisciplinary, in which many fields and outlooks are used. This mean the study of criminology is micro in nature because behaviour can be analysed in depth form different angles of approach. According to Sellin, criminology can include the realms of politics (such as left and right realist approaches to criminal behaviour and prevention strategies), psychology (such as biological and social theories for the onset of criminal activity)Read MoreSociology Of Crime : Policing1392 Words   |  6 Pageswhen the police is asking for assistance in these spheres of activity. (Millie, 2014, 4-5). Another original finding of the author which is, obviously, is one more contribution is that the police can and may be used more effectively not only for the purpose of crime reduction and criminals tracking and arrest, but also crime prevention which is, as per the author’s reasonable suggestion, the root of the e ntire crime problem and shall be dealt with by means of intensive provision of significant assistanceRead MoreCriminology : Types Of Criminal Personality1362 Words   |  6 PagesCriminology: Different Crimes Criminology: What is criminal personality? The term personality is used to define and describe the temperament and emotional attributes of a person. (S. Jones 2016). These behaviors are consistent and influence a person’s behavior so that a person may be compelled to act in the manner almost daily. The term criminal personality means a person who is of the nature to commit crime due to their temperament, ways of thinking, feeling and acting. In this paper there willRead MoreThe Rise Of The Hippy Culture In 1960S Challenges The Cultural1874 Words   |  8 Pagesunderstanding post-modern deviant behaviour, it is unnecessary to use the old criteria in deviance and crime, as it will only lead to negative side-effects. Thus, new set of theory was formed to make sense on what was happening on 1960s and all fall under the umbrella of Critical criminology. As new cultures are forming, also influences the evolution of the fashion industry, as it reflect the contemporary society, thus, incorporating a more ‘naturalâ€⠄¢ look (Welters 2008). These types of clothing, complimentsRead MoreJuvenile Female Sex Offenders : Offender And Offence Characteristics933 Words   |  4 Pages9/17/14 Juvenile Female Sex Offenders Wijkman, Miriam, Catrien Bijleveld, and Jan Hendriks. Juvenile Female Sex Offenders: Offender And Offence Characteristics. European Journal Of Criminology 11.1 (2013): 23-38. European Journal Of Criminology. Web. 14 Sept. 2014. http://euc.sagepub.com/content/11/1/23. For this critical paper I evaluated the article, Juvenile Female Sex Offenders: Offender And Offence Characteristics†. This article conforms to the library help for being a scholarly article by theRead MoreThe War On Drug: Reasons Behind The Criminalisation of Drugs and Functions of Crime In Society1255 Words   |  6 Pages(Provine, 2011, p.45). This essay focuses on the disproportionality of incarceration rates between African and Anglo Americans, and illustrates the unequal operation of law enforcement on African-Americans (Provine, 2011). This essay applies Marxist criminology to argue that the drug war is a manipulation of the law and system by the upper class to maintain their status and power over the lower class (Bradley Walters, 2012). Therefore the drug war is not essentially focused on ‘illicit’ drugs, but focuses