68 



INTRODUCTION. 



Species. 

 Ant-eater 

 Pangolin . 



Weasel-headed Armadillo 



Chlamyphorus 



Elephant 



Wild Hog . 



Tapir . 



Collared Peccary . 



Rhinoceros 



Hippopotamus 



Duyong . 



Camel . ",.. .'- 



Dromedary . . . ,;" 



Stag . .'..-.. 



Giraffe 



Gazelle * . 



Sheep . . 



Ox . . . . 



Horse . . . u 



Quagga . . .r. 



Seal, Phoca vitulina . 



Dolphin . . . 



Porpoise . . . % 



Dorsal. 



Lumbar. 



Sacral. 



Caudal. 



13) 

 13> 



Total number sixty-six. 



Thus far the more essential parts of the skeleton have been consi- 

 dered in a general point of view : those parts which every mammiferous 

 animal must possess, and which, modified as they may be in the several 

 groups of which this class consists, still retain so striking a resemblance 

 to each other, as to leave us in no doubt with respect to the unity of the 

 plan upon which they were modelled and arranged. Those less essential 

 parts of the skeleton, the extremities, or limbs, now demand attention ; 

 and though here the same unity of design prevails, yet so great a dis- 

 similarity, as regards their particular conformation, exists among Mam- 

 malia, from Man downward to so great a degree of modification are 

 they subject, so different are the uses to which nature appropriates theni, 

 that, at first, their structural relationship is not very cognizable. Upon 

 examination, however, it is found that this relationship does exist, though 

 it is not equally palpable in every instance. The modifications of parts, 

 moreover, do not proceed in a regularly progressive order, as we advance 

 along the chain of being : the alterations are, as it would appear, fluc- 

 tuating, and depend upon the purposes for which the organs are especially 

 designed, whether as graspers, wings, scrapers, simple columnar sup- 

 ports, instruments of destruction, or paddles. Multiform, therefore, 

 are the changes which exist, and great is the range of variation, among the 

 organs of locomotion, in the Mammalia, from Man, through the ter- 

 restrial and aquatic quadrupeds, to the ocean-born Cetacea, in which 



