PELVIS. 



that it is not sufficiently so to constitute a tablish separate generic classifications of the 



greater distinction than that of variety, and is human species. 



not exclusive enough in its peculiarities to es- In the Sii/(c, and those even which most 



COMPARATIVE PELVIC DIMENSIONS. 



closely approach in osseous conformation the 

 human race, as in the genera Pithecus and 

 Troglodytes, the form of the pelvis is suffi- 

 cient, at a glance, to distinguish them even 

 from the Bushman and Australian, which 

 have been seen to present all the pelvic pecu- 

 liarities of the higher varieties of humanity. 



An inspection of the foregoing table will at 

 once show this in the pelvic diameters. It 

 will be seen that the antero-posterior dia- 

 meters in the Chimpanzee, Uran-utan, and 

 Gibbon prevail greatly over the transverse ; 

 that the depth both of the whole and the true 

 pelvis is much greater^than in the human pelvis ; 

 and that the sacrum is much narrower, espe- 

 cially in the Chimpanzee, and the ischial spines 

 more closely approximated. The. sacro-ver- 

 tebral angle, too, is remarkably increased, es- 

 pecially in the Chimpanzee (160), the sacrum 

 being placed much more nearly in the direc- 

 tion of the whole spinal column, and having a 

 less vertical, as well as a much less horizontal 

 curvature, with no sacral promontory in the 

 Chimpanzee, and little in the Uran ; while the 

 coccyx is straighter, and placed more in the 

 line of the spinal column, and its tip is ele- 

 vated above the level of the upper border of 



the symphysis pubis, so that the whole of the 

 sacrum and coccyx is seen in front view. (See 

 fig. 92.) 



This high position of the coccyx is owing 

 partly to the shortness of the sacrum, -which is 

 composed of three large flat vertebrae, all 

 entering" into the formation of the sacro-iliac 

 joint, and united by ankylosis to two of 

 the four coccygeal pieces in the Uran, and to 

 one only in the Gibbons. In the Chimpanzee, 

 however, there are four sacral vertebra;, all 

 articulating laterally with the ilia, and the 

 anterior sacral foramina are very small. The 

 coccy.v is composed of five vertebra;. 



The ilia are much longer, thicker, more 

 massive, and narrower, and present no central 

 transparent portion nor internal fossa, being 

 flat anteriorly and concave posteriorly, there- 

 verse of the human ilia, and looking almost 

 directly backwards and forwards, and very 

 little inwards and upwards ; so that, in these 

 animals, there cannot be said to be any false 

 pelvic cavity. In the Uran of the Hunterian Mu- 

 seum they are two thirds of the femurs in length, 

 and measure 6 inches, and in the Chimpanzee 

 7 inches, reaching as high as the third lumbar 

 vertebra. From the limited expansion of the 



