MUSCULAR SYSTEM. 779 



region it is likewise of great importance, the occipito-frontalis, the 

 corrugator supercilii, and other muscles connected with the expression 

 of the countenance, being indubitably but portions of the fleshy pannicle. 

 In the palm of the hand it is slightly visible, forming the palmaris 

 brevis ; and even the little muscles connected with the external ear may 

 be referred to the same series. 



(2241.) In Whales, no pelvis or posterior extremities exist; it is 

 needless, therefore, to remark that the whole of the muscular system 

 appropriated to those parts in higher animals must be totally wanting ; 

 but, in return, the muscles connected with the caudal portion of the 

 spine are amazingly powerful, so as to render the horizontally-expanded 

 tail an instrument of propulsion adequate to the necessities of these 

 unwieldy animals. A large triangular muscle is found in the CETACEA, 

 apparently replacing the quadratus lumborum, thepsoas, and the iliacus, 

 which arises from the lower surface of the last rib, from the last dorsal 

 vertebra, and also from those of the loins and sacrum : from this power- 

 ful assemblage of muscular fasciculi, tendons are given off, to be inserted 

 into the lower surface of the bones that support the tail, converting this 

 organ into a mighty oar, adapted by its position to bring the creature 

 with all speed to the top of the ocean in search of air. It is, as might be 

 supposed, in the muscles of the limbs that the most important differences 

 exist. In the anterior extremities, for example, the presence or absence 

 of a clavicle will materially affect the disposition of the muscles of the 

 shoulder, as will also the existence of a coracoid process to the scapula ; 

 nevertheless in their general arrangement they conform to those of Man. 

 The rhomboid muscles, which to creatures walking on all-fours must be 

 important agents, are generally found in quadrupeds to take their origin 

 as far forward as the head : the serrati magni, likewise, whereby in the 

 prone position the weight of the body is as it were suspended from the 

 scapula, must be immensely strong. 



(2242.) The muscles acting upon the arm are similar in all the Mam- 

 malia ; but in the fore-arm, as might be expected from the very variable 

 condition of this part of the skeleton, the disposition of the muscular 

 system varies too, and even the existence of many muscles could not be 

 expected : thus as the movements of pronation and supination are, from 

 the immoveable condition of the bones of the fore-arm, impracticable in 

 the CETACEANS, the EUMINANTS, the SOLIPEDS, and others, the pronators 

 and supinators are denied ; or, if their representatives exist, they become 

 simply assistants in flexion and extension. The flexors and extensors 

 of the wrist are pretty constant ; but the muscles devoted to the hand 

 and fingers vary in almost every order. The palmaris longus, although 

 generally present where the hand is flexible, is wanting where its action 

 upon the palmar fascia would be useless, as for example in the Ungulate 

 tribes. 



(2243.) In quadrupeds there are two extensor tendons appropriated 



