673 



REPTILIA. 



REPTILIA. 



574 



gradually removed during gestation. The most characteristic differ- 

 ence is that it lives in a medium of water, and not of air, and 

 consequently does not breathe by lungs, but has the blood which is 

 deteriorated by circulating through the system purified in some 

 mariner in passing through the placenta. The umbilical vein carries 

 the blood from the placenta to the foetus : it enters the liver by the 

 longitudinal fissure, and in the tranverse fissure communicates with 

 the vena portae, sending the greater part of the blood to be circulated 

 in the liver. This organ is of great size, and seems to perform same 

 important office in the fetal economy. It is conjectured by Dr. R. Lee 

 to secrete albuminous matter, which nourishes the foetus. The rest of 

 the blood is transmitted directly to the vena cava inferior by the 

 ductus venosus, which seems to be a continuation of the umbilical 

 vein in man, though in most animals it is merely a branch arising 

 from the sinus of the vena portto. The blood conveyed by the vena 

 cava inferior to the right auricle of the heart, does not all pass, as in 

 the adult, into the right ventricle, but a great portion goes imme- 

 diately into the left auricle through an opening in the septum of the 

 auricles called the foramen ovale, which closes up immediately after 

 birth. The blood that still goes into the right ventricle through the 

 auriculo-ventricular orifice is propelled into the pulmonary artery, 

 but, as there is no use for it at present in the lungs, it nearly all passes 

 through a vessel named the ductus arteriosus into the aorta. This 

 duct also becomes obliterated after birth, its functions having ceased 

 when once the child has breathed. 



By the aorta the blood is sent from the left side of the heart and 

 ductus arteriosus to the different parts of the body, from which it is 

 returned by the veins, but a great part of it passes out of the body of 

 the foetus by the umbilical arteries, which are continued from the 

 internal iliacs, and pass out at the navel to go to the placenta. The 

 blood of the foetus differs in its physical and chemical qualities from 

 that of the adult. There is before birth no distinction between arterial 

 and venous blood ; it is of a dark colour in both systems of vessels. 

 The purified blood is brought from the placenta by the umbilical 

 vein, and is mired before arriving at the heart with that which 

 has been circulating through the foetus : the mixed blood is then 

 transmitted by the aorta to various parts of the body ; some of it 

 only going again to the placenta by the umbilical arteries to be again 

 purified. 



The position of the child in the uterus is that which takes up the 

 least room ; it lies with the head downwards, the chin being bent on 

 the breast ; the knees are doubled up close to the belly, and the arms 

 are folded in the space between the head and legs. This is the moat 

 general position, and the child thus forms an oval figure, of which the 

 head forms one end and the breech the other. The long axis of this 

 ellipse measures in the ninth month fully ten inches, and the short 

 one five or six inches. The quantity of fluid which surrounds the 

 child at the full time is, on an average, about two pints. 



The ordinary period of utero-gestation in man is forty weeks, 

 though labour often takes place before this period, or is delayed a 

 little beyond it. The embryo having now arrived at a sufficient 

 degree of maturity to exist separately, the fibres of the uterus con- 

 tract, accompanied by contraction of the abdominal muscles and 

 diaphragm. In consequence of this pressure the membranes gradually 

 dilate the mouth of the womb; they then burst and evacuate the 

 liquor amnii, when the pressure acts upon the child itself, which is 

 gradually forced into the world, and commences a new existence. In 

 man, and other Mammalia, the young being for a considerable time 

 depends upon its mother for the whole of its nourishment, and very 

 generally requires a supply of warmth and a degree of protection till 

 it is able to provide for itself. 



REPTILIA, a class of Animals belonging to the sub-kingdom 

 Yertebrata, and embracing the creatures usually known as Crocodiles, 

 Lizards, Turtles, Tortoises, Frogs, Toads, and Serpents. In the articles 

 AMPHIBIA, CROCODILID^ CHELONIA, OPIIIDIA, and SAURIA, will be 

 found an account of the principal forms and organisation of these 

 creatures. We here propose to give a slight sketch of their history, 

 and the attempts made at their general classification. 



The ancient monuments of the Egyptians prove that the great 

 groups of the tortoises, the lizards, the serpents, and the frogs, as well 

 an their habits, were well known to that people; and the Sacred 

 Scriptures abound in passages (the Old Testament especially) showing 

 that a similar knowledge obtained when they were written. Indeed 

 from the earliest times these forms must have attracted the attention 

 of man ; and a natural desire on his part to ascertain which of them 

 were dangerous, and which were innocuous, must have led him to 

 particular inquiry in order to solve the doubt. 



In Herodotus and Athenxus there are not wanting passages 

 indicative of precise notions respecting many species of reptiles. 



That this class of animals hnd employed no small portion of the 

 acute observation of Aristotle, and that he was well acquainted with 

 their form, structure, and habit, appears from the great work which 

 has juat'y immortalised him as a zoologist. We need only refer to the 

 following passages in his ' History of Animals ' to be well satisfied of 

 the Jact (lib. i., c. 1.; lib. ii., c. 10, 17; lib. v., c. 3, 4 ; lib. viii., c. 

 2, 17). We find noticed the oviparous quadrupeds, namely, the laud 

 ami marine Tettudinata, the crocodiles, the lizards, &c. ; the serpents, 

 with au abtemtioa that tliey may be placed at the side of the lizards, 



as resembling them closely, if we suppose the lizards to be lengthened 

 and deprived of their feet. The frogs are also often mentioned. 

 Aristotle was quite aware of the generation of most of this class ; he 

 knew that' the viper was ovoviviparous, and states that it brings forth 

 its young alive, having produced an egg internally (6 jj.lv x'S *("> 

 aioTOK?, Iv avrui irpuroif o>oT<JK7j<ras) ; and he indicates what animals 

 should be designated as Amphibia. 



Pliny writes much and elegantly concerning this class; but the best 

 of his observations are borrowed from Aristotle, and his far from well- 

 digested compilation is mixed up with so great a portion of error and 

 so large a measure of credulity, as justly to merit the censure passed 

 by Cuvier on this voluminous and pleasant author, but too often 

 fabulous natural historian. 



Darkness settles on the period from the fourth to the ninth century 

 as far as the history of the sciences is concerned ; but at that epoch 

 the best Greek works were translated by the Arabs, who thus handed 

 on the most curious known facts, especially those which had any 

 reference to the art of medicine. Again there is a great void till the 

 early part of the sixteenth century, when France produced Belon and 

 Rondeletius, Italy Salviani, and Switzerland that prodigy of erudition, 

 as he is designated by Boerhaave, Conrad Gesner. Two of Qesner's 

 books are devoted to the natural history of reptiles lib. ii., ' De 

 Quadrupedibus Oviparis ;' and lib. v., ' De Serpentium Natura.' 



Towards the end of the same century Aldrovandi appeared. The 

 results of fifty years' research in collecting objects of natural history, 

 the drawings which he caused to be made of them, and his diligent 

 studies relative to every point bearing on their history, appeared after 

 his death, which happened in 1605, in fourteen volumes folio. The 

 two books upon serpents and lizards do not appear to have been 

 published till 1640, when they were given to the world by Professor 

 Ambrosini of Bologna : twenty-two chapters are occupied by the 

 serpents, and six only are dedicated to basilisks, dragons, and other 

 lizards, the greater part of which however are fabulous. 



Jonston's ' Historia Naturalis," edited by Henry Ruysch, son of the 

 celebrated anatomist, under the title of ' Theatrium Universale Omnium 

 Animalium,' is principally a selection of the remarks of those who 

 preceded him, and he has but few observations which can be called 

 his own ; still fewer indeed than Aldrovandus, who does not abound 

 in originality. 



But it is to our countryman John. Ray that we owe the first arrange- 

 ment which can be truly called systematic : in his ' Synopsis Methodica 

 Animalium Quadrupedum et Serpentini Generis,' which first appeared 

 in 1693, we have a classification based on the mode of respiration, the 

 volume of the eggs, their colour, &c. This basis is not indeed 

 strengthened by any description of the habits or organisation of the 

 reptiles on which he treats, and cannot but be considered as insuf- 

 ficient; still it is valuable, and has the merit of leading the way to 

 more accurate methods. 



The Amphibia form, in the last edition of the 'Systema Naturae,' 

 published by Linnaeus himself, the third class of the animal kingdom. 

 This class consists of three orders : 



1. Reptilet, which are described as ' pedati, spirantes ore.' 



2. Serpentes, which are characterised as ' apodes, spirantes ore." 



3. Nantes, which are characterised as ' pinnati : spirautes etiam 

 branchiis lateralibus.' 



The last order, which consists of cartilaginous and other fishes, 

 forms no part of our present inquiry, which is confined to animals 

 included in the two first. 



The Reptiles are thus designated : ' Oa respirans pulmonibus. 

 Pedea quatuor:' and they consist of the genera Testudo (Land, 

 Marine, and Fresh- Water Tortoises) ; Rama (Frogs and Toads) ; Draco 

 [DRACONIKA]; and Lacerta, which includes the Crocodiles and the 

 rest of the Saurians. 



The Cerpentes have the following general character : ' Os respirans 

 tantum pulmonibus. Pedes nulli, pinnaove natatorioo nullac. Aures 

 nullaj;' and they comprise the following genera : Crotalus (the Rattle- 

 Snakes) ; Boa (Boas and Pythons) ; Coluber, including all serpents 

 which have abdominal scuta and subcaudal scales, whether poisonous 

 or not; Anguis, including the Slow-Worms, Bipa and other serpents, 

 the poisonous Cerastes, &c. ; Amphiabiena ; and Cacilia. 



The work on Oviparous Quadrupeds, published by Klein in 1751 

 'Quadrupedum Dispositio Brevisque Historia Naturalis' requires 

 hardly any notice, and another which made its appearance in 1756 

 'Tentamen Herpetologise' deserves as little. The latter, notwith- 

 standing its extensive title, treats only of serpents ; and the value 

 of the criticisms of this opponent he cannot be called rival of 

 Linnaeus may be appreciated by his arranging in the same category 

 the Earth- Worms, Tape- Worms, and Leeches. 



But it ia to the ' Specimen Medicum ' presented by Laurent! at 

 Vienna, in order to obtain the degree of Doctor, that we must look 

 for the first well-digested history of reptiles. This remarkable work, 

 which omits the Tortoises, but. in other respects may be said to have 

 formed an era in the science of Herpetology, is divided into two parts : 

 the first relates entirely to the natural history and characters of the 

 genera ; the second is devoted to specific descriptions, and the record 

 of experiments made to detect the existence of poison in some species, 

 and the effect of remedies in certain cases. But though this most 

 able treatise is always quoted as that of Lnurcnti, it has born 



