775 



5111. The sacrum. 



The first vertebra of this is homologous with the last lumbar in Man, and with the same 

 vertebra in the skeleton of the female Chimpanzee, No. 5082, where, however, although free, 

 it exhibits a similar modification to the present by a sudden increase of size of the transverse 

 process, due chiefly to the development of its backwardly projecting or anapophysial part. 

 The second sacral vertebra does not exceed the first in breadth ; the rest slightly diminish 

 to the fifth. The neural arch is complete in each, and the spinous process is developed from 

 all but the last, the four posterior spines being confluent. The metapophyses are developed 

 from the four anterior sacrals : the three anterior ones join the iliac bones. 



5112. The three coccygeal vertebrae. 



The first has rudimental neurapophyses answering to what have been termed the ' shoulders 

 of the os coccygis ' in Anthropotomy, and a pair of short, depressed diapophyses : the two 

 terminal vertebrae consist of the centrum only, and are confluent. 



5113. The manubrium sterni and first pair of thoracic ribs. 



The ribs are shorter and their neck relatively longer than in the Orang, and they are more 

 curved. The manubrium sterni is more compressed superiorly, where, instead of being 

 flattened, it is rounded off, and presents two low and broad tuberosities : it also contracts more 

 towards its lower end, and is longer in proportion to its breadth. In all these characters it 

 approaches, in form, nearer to the same part in Man. 



5114. The second pair of thoracic ribs. 



5115. The seven succeeding pairs of thoracic ribs. 



5116. The tenth pair of ribs. 



The articular tubercle is well marked. 



5117. The eleventh pair of ribs. 



These have an articular tubercle well marked, but nearer the head than in the foregoing 

 pair. 



5118. The twelfth pair of ribs. 



In this pair, also, the articular tubercle is distinctly developed, and is a little nearer the 

 head. The rib is rather shorter than the preceding, but has the same degree of curvature. 



