THE SKELETON 



man, about halfway between the center and the edge along 

 each side is a row of four nearly round holes. Across the 

 surface of the bone is a dim, transverse line, or seam, 

 between each pair of holes, from which it is seen that five 

 smaller sections of the spinal column have anchylosed, or 

 grown together, to form the sacrum. The holes coincide 

 with the open spaces between 

 the transverse processes, or 

 lateral projections, of the other 

 bones of the spinal column 

 above this. In the chimpan- 

 zee this bone has the same 

 general form as in man, except 

 that instead of four holes in 

 each row it has five. They 

 are connected by transverse 

 seams the same as in man, 

 thus indicating that six of the 

 vertebrae, instead of five, are 

 united. In compensation for 

 this, the ape has one vertebra less in the portion of the spinal 

 column just above, which is called the lumbar. In man 

 there are five free lumbar vertebrae and five united sections 

 of the sacrum, while in the ape there are only four free lum- 

 bar vertebrae and six united sections forming the sacrum. 

 But regarding each section of the sacrum as a separate 

 bone and counting the whole number of vertebrae in the 

 spinal column there are found to be exactly the same 

 number in each. 



Some writers have put great stress upon the difference 



Pelvis of the Chimpanzee 



A, sacrum; B, fourth lumbar vertebra; C, 

 coccyx; D, ilium or hip bone; E, femur 

 or thigh bone. 



