4 Dynamic Theory. 



Again, the number of vertebrae in the human backbone is usually 29, 

 not counting the 3 or 4 bones of the coccyx or rudimentary tail. These 

 bones are divided into 7 cervical or neck bones, 12 dorsal or rib bones, 



5 lumbar bones without ribs, and 5 . united into one called the sacrum. 

 The gorilla has the coccyx or tail bone same as man. His cervical and 

 dorsal vertebrae together make 19, same as in man, but the gorilla has 

 always one more and sometimes two more pairs of ribs than the usual 

 12 pair in man, the extra ones attached to lumbar vertebrae leaving the 

 lumbar vertebrae less in number than in man. Occasionally in man the 

 number of ribs varies from 12 pairs, there being sometimes 13 ribs and 

 4 lumbar vertebrae. Once 11 ribs and 6 lumbar vertebrae, and of ten 

 more than 6 lumbar vertebrae, are said to have been observed. In this 

 matter, as in the case of the lengths of limbs, the gorilla differs as much 

 from his brother apes as from man. One orang-utan skeleton is ob- 

 served to have 12 dorsal and 5 lumbar A^ertebrae same as man, and the 

 same was observed in a gibbon. Among the lower apes some have 12 

 dorsal and 6 or 7 lumbar ; some have 14 dorsal and 8 lumbar and some 

 have 15 dorsal and 9 lumbar vertebras. 



Again comparison is made between the gorilla, the gibbon and man 

 in the matter of the broad pelvic bones that support the viscera, show- 

 ing that those of the gorilla, although smaller and less developed than 

 man's, are more like his than they are like those of the gibbon. 



Comparative Table of Vertebra}. 



No. neck Dorsal Lumbar Cross Tail Total 

 vertebrae, vertebra?, vertebrae, or sacral, vertebrae 



{ Man 7 12 5 5 4 33 



^ I Orang 7 12 5 4 5 33 



| | 



' Gorilla 7 13 4 4 5 33 



Chimpanzee 7 14 4 4 5 34 



Mandrill (Mormon Choras) 7 13 G 3 5 34 



Drill (Mormon Leucophaeus). .7 12 7 3 8 37 



Rhesus (Innuus rhesus) 7 12 7 2 18 46 



I Sphinx (Papio sphinx) 7 13 6 3 24 53 



[ Simpai (Semnopithecus Melus). 7 12 7 3 31 60 



Next compare brains and skull capacity. The largest human skull 

 observed by Morton of Philadelphia, had a capacity of 114 cubic 

 inches ; the smallest observed by anybody had 62 inches capacity. The 

 capacity of the gorilla's skull ranges from 24 to 34|- inches. Thus in 

 cranial capacity there is greater difference amongst men than between 

 the lowest man and the highest ape. It is also stated that the lower 

 apes fall below the gorilla in cranial capacity almost as much relatively 

 as he falls below man. 



