66 INTRODUCTION. 



of the transverse processes, and united, end to end, like the joints of 

 the fingers, decreasing as they proceed ; but without any canal for the 

 prolongation of the spinal chord. In some, however, they assume a more 

 important character, and constitute the framework of an organ intimately 

 connected with the peculiar economy of the species. In the Sapajou 

 Monkeys of South America, for example, which have the tail adapted 

 for grasping, and by which they are assisted in their progress among 

 the branches, there is, at the base of each of the caudal vertebrae, on its 

 under surface, two processes, between which the tendons of vigorous 

 muscles of flexion are continued. 



The Beaver is another example in point. Using its broad scaly tail 

 as a paddle and rudder, the action being an up-and-down stroke, as in 

 the Porpoise and Whale, the transverse processes, accordingly, are not 

 only not obliterated, but remarkably broad and large, indicative of 

 the development of the muscles by which the tail is influenced. The 

 Porcupine also may be adduced. In this animal the transverse processes 

 of each caudal vertebra are less remarkable than the spinous : the tail 

 is covered with a forest of quills, which are capable of being strongly 

 agitated; and hence the development of the spinous processes, for the 

 attachment of the necessary muscles. 



1 With regard to the lumbar, sacral, and caudal portions of the verte- 

 bral column of the Cetacea, no rigid or definite line of demarcation sepa- 

 rates the one part from the other : in fact, no distinction exists among 

 them. The Cetacea have not a true pelvis ;* and, consequently, no hind 

 limbs : their body tapers off like that of a fish, and ends in a horizontal 

 fish-like tail. It may, however, be remarked, that the large transverse 

 processes, which so strikingly characterize the primary lumbar vertebrae, 

 gradually diminish, as the vertebrae approach the tail ; and, in the several 

 ultimate vertebrae, they disappear entirely. 



The following table of the number of the vertebrae in Mammalia is 

 taken, partly from data collected by Cuvier (see his work on Comparative 

 Anatomy), but chiefly from facts, which have fallen under the Author's 

 personal observation. 



Species. Dorsal. Lumbar. Sacral. Caudal. 



Man 12 ... 5 ... 5 ... 4 



Orang-outan . . . 12 ... 4 ... 5 ... 3 



Chimpanzee . . . 13 ... 4 



Hoolock Gibbon . . 13 ... 5 ... 4 ... 3 



Capuchin Monkey . . 12 ... 7 ... 3 ... 21 



Patas . . . . 12 . . . 7 . . . 3 . . . ? 



Proboscis Monkey . . 12 ... 7 ... 3 ... 23 



Bonnet Monkey . . 12 ... 7 ... 3 ... 20 



* The rudiments of the pelvic bones may be detected in the Cetacea, but nothing more. 



