ANATOMICAL STRUCTURE OF ANTHROPOID APES. 129 



hinder borders of the ilia, although the second of 

 the lower lumbar vertebrae is somewhat higher than 

 the top of the crest of the ilium. This is still more 

 remarkably the case in an old male chimpanzee, in 

 which the lowest lumbar vertebra seems to be wedged 

 in between the two ilia. In a young male chim- 

 panzee, and in the adult female, both the lower 

 lumbar vertebrae are almost compressed between 

 the upper segments of the ilia. In the orang the 

 lowest lumbar vertebra is placed between the ilia. 

 Out of the five sacral vertebrae the first and second 

 are articulated with these bones. 



In the gorilla the highest sacral vertebra, the 

 twenty-fifth of the series, is the fulcralis. In this 

 animal the first to the third sacral vertebrae form 

 part of the connection with the crests of the ilia. 

 In the chimpanzee the twenty-fifth is also the ver- 

 tebra fulcralis, and from the first to the third are 

 likewise connected with the ilia, but the third only 

 to a limited extent ; and in young males and in old 

 females the connection is generally confined to the 

 first and second sacral vertebrae. In the orang-utan 

 the twenty-fourth vertebra is generally i\xe fulcralis. 



In the gibbon the twenty-fifth vertebra is usually 

 the fulcralis. In the siamang I found that the fifth of 

 the five lumbar vertebrae was between the ilia. 

 Out of the five sacral vertebrae the first and second 

 were articulated with the said pelvic bones. In 

 Hylohates agilis the fifth and sixth of the six lumbar 

 vertebrae were between the ilia, and the first and 

 second of the five sacral bones were articulated with 

 these. 



