MUSCULAR SYSTEM. 11 



muscles analogous to the psoas and the iliacus, which power- 

 fully assist in the downward movements of the coccygeal 

 vertebrae. The oblique, the transverse, and the recti mus- 

 cles of the abdomen are lengthened and feeble on the long 

 trunk of the cetacea, and the abdominal ring is wanting, 

 as in other mammalia, where the testes remain permanently 

 in the abdominal cavity. The proximate muscles of the an- 

 terior extremities, the subscapular, the infra-spinati, the pec- 

 toral and the deltoid muscles, are those principally employed 

 in the movements of these fin-like organs. The more distant 

 muscles of these extremities, however, especially the flexors 

 of the fore-arm and hand, are much more developed in the 

 herbivorous cetacea, which are able to seize and to climb 

 upon rocks. The muscles of the pharynx, of the os hyoides, 

 and of the exterior nares, are numerous and distinct in these 

 animals, and correspond with the magnitude and the mobi- 

 lity of these parts. The compressor muscles, embracing the 

 expanded nostrils of many of the blowing cetacea, enable 

 them forcibly to expel columns of water taken in by the 

 mouth, and the extension of these muscular cavities allows 

 them to breathe freely while the rest of their body is beneath 

 the surface of the water. The cetacea, like fishes, amphibia, 

 and serpents, consisting almost solely of the trunk, are 

 moved and supported by its muscles in the dense element 

 they inhabit ; but the land quadrupeds require strong mem- 

 bers and strong muscular apparatus to support and move 

 their heavy trunk in the light and unresisting element they 

 breathe. In the herbivorous quadrupeds, the muscular 

 energy and development are generally less than in the car- 

 nivorous species, which corresponds with the inferior deve- 

 lopment of their respiratory and nervous systems, and the 

 diminished activity of all their functions. The ruminantia, 

 like the pachyderma, having no clavicles, the humeri are ap- 

 proximated under the thorax, and the anterior part of the 

 trunk is suspended between the long vertical scapulae by the 

 strong serrati muscles, as by a band passing across beneath 

 the chest. From the weight and the horizontal position of 

 the trunk, the extensor muscles of the extremities are more 

 developed than the flexors, and to render these extremities 

 more light and nimble, the distal bones and tendons are 

 lengthened, and the heavy fleshy parts of the muscles, as in 



