Evolution of Animals 501 



lemurs, without passing through the monkeys proper. This 

 close association of man with the apes is based on various 

 considerations. One of them is that the skeleton of the anthro- 

 poid apes more nearly resembles that of man in the most 

 important respects than it does that of the monkeys. This 

 is especially true of the vertebral column, where the anapo- 

 physes are wanting in the Anthropomorpha (insignificant 

 rudiments- remaining on one or two vertebrae, as pointed out 

 by Mivart), while they are well developed in the monkeys 

 and lemurs. The molar teeth of the apes and man resemble 

 each other more than do those of the monkeys, since they lack 

 the crests which connect the cusps, which are general in the latter. 



*'The frequent presence of the tritubercular molar in man 

 suggests the superior claim of the lemurs over the monkeys 

 to the position of ancestor, x^nother significant fact pointing 

 in the same direction is the existence of large-brained lemurs 

 with a very anthropoid dentition (Anaptomorphidfe) in our 

 eocene beds, which have the dental formula of man and the 

 Old World monkeys and apes." And later (p. 156) he adds: 

 "I now maintain as a working hypothesis that all the Anthro- 

 pomorpha were descended from the eocene lemuroids." 



It is unnecessary in this chapter to do more than refer to 

 the general opinion of naturalists that the genus Homo is not 

 directly derived from any one of the highest living apes, but 

 is descended rather from a form that combined various char- 

 acters of these in more or less intimate blending, at the same 

 time that steadily evohdng characters were superadded to 

 these, which gradually gave him his dominant position. 



Summing up then the conclusions indicated in the preceding 

 chapters it may be said that, from a unicellular ciliate infu- 

 sorian, the main line of progressive evolution has been pursued 

 through a loosely multicellular ciliate type somewhat inter- 

 mediate between infusorian and rotiferan organisms. From 

 this direct advance has been made through the Rotifera and 

 Rhabdocoela to the Nemertinea, the latter of which, in the 

 fresh-water forms especially, more and more closely foreshad- 

 owed and advanced toward future vertebrate organization 

 as strongly advocated by Hubrecht. While such Hemichor- 



