46 



hedge-hog, and the porcupine, and those covered with scales, as the 

 rnanis and the armadillo, this muscle is important in erecting or 

 moving these epidemic organs, and in coiling or uncoiling the body. 

 In the mole, and those animals that dig the earth, the flexors of the 

 arm, the pectoralis major, the latissimus dorsi, and the teres major, 

 are of vast size. In the rodentia, the muscles are pale, and those of 

 the jaws of great magnitude. The marsnpiata have the panniculus 

 carnosus extended over the pouch in such a manner as to support 

 the young abortive-like fretus, and force the mammary secretion 

 into its mouth. The arrangement of the muscles approaches nearer 

 to the human type in the quadrumana than in any others of the 

 mammalia. In them the flexor muscles are strongly developed on 

 all their extremities. The thumbs, have no long separate flexors, 

 but receive tendons from the flexors of other fingers. r ^ ne P^ an ~ 

 taris muscle, which is very fleshy in monkeys, instead of termina- 

 ting, as it does in man, by insertion in the os calcis, passes over that 

 bone to be connected with the planter fascia and flexor perforatum. 

 In other quadrupeds it passes over the os calcis to the sole of the 

 foot, and supplies the place of the flexor digitorum brevis. The 

 glutaeus maximus, which is the largest muscle of the human body, 

 is small and feeble in the simise and other animals, its chief use being 

 to support the trunk upon the lower extremity, and thus assist in 

 maintaining the erect attitude, and not, as the pious Spigelius 

 imagined, to form a soft cushion for the body to rest on during 

 divine cogitation. 



Finally, the extensors of the knee, the flexors of the toes, and the 

 other muscles forming the calf of the leg. are relatively larger in the 

 human subject than in any other animal. 



RECAPITULATION. 



1. Muscular fibres have been satisfactorily shown to exist in the 

 higher species of the radiata. 



2. Muscle is found all through the articulate and molluscous 

 classes, but better and more uniformly developed in the former. 



3. The soft parts are uniformly placed external to the hard, in 

 the vertebrated classes. 



4. The muscles in fishes are generally soft and pale, as in the 

 lower classes. 



5. In the amphibia, the muscles present different characters in 

 the tadpole and adult state. 



6. Great variety in the reptiles, chiefly referable to their diversi- 

 fied habits. 



7. The muscular system in birds is characterised by great 

 uniformity throughout the class. 



8. The muscles of the aquatic mammalia resemble those of 

 fishes. 



9. Serrati magni greatly developed in the quadrupeds not pos- 

 sessing clavicles. 



