98 INTRODUCTION. 



Orang Outan ; let his small ill-fashioned legs, incapable of supporting his 

 body upright, be compared with the long muscular arms, of superhuman 

 strength, by which he swings himself from tree to tree with astonishing 

 agility. The same law prevails in the burrowing Insectivora, the Mole, 

 and the Chlamyphorus ; in the Echidna and the Armadillo ; and in the 

 Carnivora generally. 



The reason of the development of the inferior extremities in the 

 human subject, is as apparent as that of their deterioration in the lower 

 races enumerated above. In earliest infancy this predominance is not 

 so apparent : the childhood of Man is a state of utter helplessness : months 

 elapse before he can commence, with tottering steps, his first locomotive 

 essay ; and years pass away before his foot is firm and free before he 

 rejoices " in the strength of his youth." During this interval, a relative 

 development of the lower limbs, beyond that of any other portion of the 

 frame, has gradually taken place, and has given to the figure its perfect 

 and true proportions. 



With the development of the lower limbs are immediately connected 

 the magnitude and the breadth of the pelvis ; it consists of two distinct 

 portions, each being united to that division of the vertebral column called 

 the sacrum ; and thence taking a circular sweep, round and forward, so 

 as to meet in the front ; thus enclosing an area, of which the sacrum 

 constitutes the dorsal, or back wall (figs. 64, 65). Each of these 

 pelvic bones was originally divided into three, meeting in the cup-like 

 cavity which receives the head of the thigh-bone ; and though, at an 

 early period, they become ossified, so as to lose all trace of their primary 

 division, anatomists still appropriate three distinct names the ilium, the 

 ischium, and the pubis to the three respective parts ; the general title of 

 pelvis (from its basin-like figure) being applied as a designation to the 

 whole. The ilium, or iliac portion, c, c (figs. 64, 65, 66, 67), consti- 

 tutes the broadly-expanded upper part, on each side of the sacrum, a : 

 the ischiatic portion, e, e, extends downward from the acetabulum, /, f, 

 whence it rises upward, forming the lower margin of a large orifice (the 

 thyroid, or ischiatic foramen), to join the pubic portion, d, d, which 

 extends from the anterior portion of the acetabulum, sweeping forward 

 to meet its fellow in the fore part of the pelvis, the two bones being 

 united together by a ligamentous cartilage. 



In no Mammalia is the pelvis so capacious, relatively, as in the human 

 subject ; for, as its development is connected with the attitude and loco- 

 motive powers of the species, and, as in no other Mammalia are seen the 

 same attitude, and the same locomotive powers, so in none, not even in the 

 Ape, does it resemble that of the human race : it varies, remarkably, 

 among different genera, in its figure, and in its relative proportions : in the 

 Cetacea it is in a merely rudimentary condition. In the Seals the iliac 



