REPT1LIA. 



285 



substance of that organ. The flexibility of 

 the tongue seems to depend entirely upon the 

 different muscular fasciculi of which these 

 muscles are composed, having the power of 

 contracting separately, some being longer or 

 shorter than others, accordingly as they ter- 

 minate successively in the proper membrane 

 of the tongue to which they are attached ; for 

 there seem to be no transverse or oblique 

 fibres constituting intrinsic lingual muscles. 



The mechanism by which the Cobra de 

 Capello, when irritated and ready to seize its 

 prey, expands the skin of the neck, giving it 

 the appearance from which the snake takes its 

 name, consists entirely of muscles, acting upon 

 the ribs and external skin of the animal. 



From the rounded form of the hood, the 

 skin has the appearance of being inflated ; but 

 the most careful examination does not discover 

 any communication between the trachea or 

 the lungs, and the cellular membrane under 

 the skin. 



In this snake, the ribs nearest the head, to 

 the number of twenty on each side, have a 

 different shape from the rest ; instead of bend- 

 ing equally with the other ribs towards the 

 belly, they go out in a lateral direction, having 

 only a slight curvature, and when depressed, 

 lie upon the side of the spine, on one another. 



In the extended state of the ribs, the skin 

 of the back is brought over them, forming the 

 hood ; and in their depressed state the hood 

 disappears. 



The ribs are raised by four sets of muscles : 

 one set from the spine to the upper edge of 

 each rib ; a second set from the ribs above, 

 passing over two ribs to the third rib below ; 

 another set have their origins from the rib 



five muscles. Of these the first is a long 

 muscular slip (fig. 207, 1.) that takes its origin 

 from the arch and spine of the first vertebra 

 of the neck, and which, together with a broad 

 triangular muscle (2), corresponding to the tem- 

 poralis, that arises from the lateral region of 

 the os-frontis and the parietal bones, is in- 

 serted in front of the os quadratum into the 

 upper margin of the lower jaw. A third 

 muscle (3), analogous to the masseter, 

 arises at the upper extremity of the os quad- 

 ratum towards its anterior 'part, and extends 

 to the external surface. The three preced- 

 ing muscles serve to close the jaws ; they 

 are antagonised by a short muscle (4>) de- 

 rived from the quadrate and temporal bones ; 

 whose attachment to the lower jaw is placed 

 behind the centre of motion of the articulation 

 of the jaw, and consequently its effect will 

 be to open the lower jaw. 



Lastly, there is an external pterygoid mus- 

 cle, provided for the lateral movements of the 

 inferior maxilla. 



Muscles of the Trunk. Running along the 

 whole length of the back there is the broad 

 lateral muscle (fig. 207, 5), which like- 

 wise forms the principal part of the lateral 

 walls of the abdomen. This muscle forcibly 

 reminds us of the great lateral masses of 

 muscle which form the principal part of the 

 body of fishes, and, in like manner, it is divided 

 by tendinous intersections into as many por- 

 tions as there are vertebrae in the spine. Its 

 commencement may be traced as far forwards 

 as the occipital quadrate and temporal bones : 

 it likewise has points of origin from the 

 spinous and transverse processes of the whole 

 vertebral column. These two lateral masses 



above, pass over one rib, and are inserted into are separated above by a deep furrow (5 a), 



111 i r A 1_ P 1- I. rll l ,. i n 



the second below ; and a fourth set pass from 

 rib to rib. The combined effect of these four 

 sets of muscles raises and extends the ribs. 



The skin of the back is brought forwards 

 on the neck, by a set of very large mus- 

 cles, going off from each of the first twenty 

 ribs on each side, a quarter of an inch from 

 their head, by a tendinous origin, which soon 

 becomes fleshy ; the longest of these muscles 

 are two inches long. They are inserted into 

 the skin, and, when the ribs have been first 

 extended, have the power of bringing the skin 

 forwards to a great extent. 



Myology of Salamander (Salamandra ter- 

 restris). In-order to complete our survey of 

 the myology of the reptilia, it has been deemed 

 advisable to introduce in this place a brief 

 sketch of the muscular system of the amphibia, 

 which is obviously arranged upon the same 

 plan as that of the quadruped reptiles pro- 

 perly so called, and from its comparatively em- 

 bryo condition is a subject of much interest.* 



which is filled up with a series of cutaneous 

 glands peculiar to these animals. The dorsal 

 portion is with difficulty separated into an 

 upper and lower stratum, of which the upper 

 and more external may be compared to the 

 sacro-lumbalis, while the lower and broader 

 one seems to represent the longissimus dorsi. 

 The cephalic extremity, having numerous 

 points of attachment in the neck, and likewise 

 the occipital region of the skull, forms several 

 muscular bundles, more or less distinct from 

 each other, which represent the muscles of 

 the neck. 



The representative of the external oblique 

 muscle of the abdomen (6), is here evi- 

 dently merely a continuation of the great 

 lateral muscle above described. In this re- 

 gion, however, it attaches itself more particu- 

 larly to the rudiments of the ribs and to the 

 contiguous transverse process of the vertebra, 

 extending from the second vertebra of the 

 neck as far back as the pelvis ; inferiorly, it 



Muscles of the Head. The movements of is connected with its fellow of the opposite 



the eye are effected in the usual manner by 

 means of the four recti and two oblique mus- 

 cles, the disposition of which is similar to 

 what exists in reptilia generally. 



The movements of the jaw subservient to 



side by a tendinous interlacement, represent- 

 ing the linea alba. 



The internal oblique muscle of the abdomen 

 is represented by the inner layer of the pre- 

 ceding. By the partial separation of these 



mastication, are performed by the agency of two muscular layers, a sheath is formed which 



* See the article AMPHIBIA. 



partially encloses the Pubo-hyoideus. 



