148 HEPTILIA. 



rectus may be distinguished, provided with many transverse tendinous 

 bands. The muscles of the extremities are more analogous to those 

 of the higher Reptilia. 



In the Frogs the muscles of the back, are much shorter, and the 

 parallel tendinous intersections are limited, as in man, merely to 

 the abdominal muscles. The dorsal region in the Frog, particularly 

 behind the head, is covered chiefly by the powerful muscles of the 

 scapula, and the very small latissimus dorsi. The temporal muscle 

 is very developed, and in like manner the strong muscles of the 

 lower law. The pectoralis major is of very remarkable strength, 

 and gives off narrow strips in the direction forward and backward, 

 and is also divided into several stout bellies ; beneath it lies the 

 small pectoral, also of considerable size. The extensors of the 

 humerus and fore-arm (m. m. deltoideus and triceps brachii) con- 

 sist of very short, but uncommonly fleshy and strong muscular 

 bellies. The flexor and extensor muscles of the hand present a 

 similar character, so that in this respect the organ obtains a form 

 analogous to that of the human subject. Upon the posterior extrem- 

 ities, on the contrary, the large glutaei are very different from 

 those of Man, appearing as short, narrow, and but slightly de- 

 veloped muscles, adapted to the elongated form of the iliac bones, to 

 which they are attached. The muscles of the legs, from the hinder 

 extremities being adapted by their length for leaping and swim- 

 ming, exhibit forms more analogous to the human structures, this 

 holding good, both with the extensor and flexor muscles, as the 

 m. sartoriuSj adductor magnus, semitendinosus and membranosus, 

 and the strong muscles of the fibula, the gastrocnemii. The strong 

 tendo-Achillis is continued into the plantar aponeurosis, and the 

 patella-like bone already alluded to, as placed between the tibia 

 and tarsal ossicles, serves it as a pulley over which to play. The 

 muscles of the feet are greatly subdivided, and their short bellies pass 

 into delicate tendons. 



The slightest or most rudimentary degree to which the muscles 

 of the trunk, including those of the back and ribs, are developed, 

 is met with in the Chelonia, by reason of the peculiar manner in 

 which their tegumentary is anchylosed to the true skeleton. The 

 muscles of the face are equally rudimentary, and upon removing the 

 hard closely overlying integument, we perceive only the temporal 

 and palpebral muscles. The muscles of the neck, and its nape, 

 are, on the contrary, well developed, particularly the m. spinalis 

 cervicis, which divides into single detached bundles, and is inserted 



