34 THE RIDDLE OF THE UNIVERSE. 



length of their bones, which were originally adapted 

 to their arboreal manner of life. Their hands and 

 feet are five-fingered, and the long fingers are excel- 

 lently suited for grasping and embracing the branches 

 of trees ; they are provided, either partially or com- 

 pletely, with nails, but have no claws. The denti- 

 tion is complete, containing all four classes — incisors, 

 canine, premolars, and molars. Primates are also 

 distinguished from all the other placentals by important 

 features in the special construction of the skull and 

 the brain ; and these are the more striking in propor- 

 tion to their development and the lateness of their 

 appearance in the history of the earth. In all these 

 important anatomical features our human organism 

 agrees with that of all the other primates : man is a 

 true primate. 



An impartial and thorough comparison of the bodily 

 structure of the primates forces us to distinguish two 

 orders in this most advanced legion of the mammalia — 

 half-apes (prosimice or hemipithecij and apes fsimice or 

 pitheci J . The former seem in every respect to be the 

 lower and older, the latter to be the higher and younger 

 order. The womb of the half-ape is still double, or 

 two-horned, as it is in all the other mammals. In 

 the true ape, on the contrary, the right and left wombs 

 have completely amalgamated ; they blend into a pear- 

 shaped womb, which the human mother possesses 

 besides the ape. In the skull of the apes, just as in 

 that of man, the orbits of the eyes are completely 

 separated from the temporal cavities by an osseous 

 partition ; in the prosimice this is either entirely 

 wanting or very imperfect. Finally, the cerebrum of 

 the prosimia is either quite smooth or very slightly 

 furrowed, and proportionately small ; that of the true 



