MONOPHYLETIC GENEALOGY. 25 I 



In specially observing the position of Man in the animal 

 system, it cannot be doubted for a moment that the entire 

 bodily structure of Man is that of a Vertebrate, and that 

 Man possesses in the characteristic position and combination 

 of his organs all those peculiarities which appear only in 

 the Vertebrate class, and are totally wanting in all other 

 animals. The Vertebrates are either in no way related to 

 the three other higher groups of animals, or they are so 

 only in their common descent from the Worms and from 

 the Gastraea ; on the contrary, a relationship really exists,, 

 and may be clearly proved between Vertebrates and some 

 forms of Worms. I may now enunciate the proposition, 

 which we shall hereafter prove, that the entire Vertebrate 

 tribe has developed from the Worm tribe. On the other 

 hand, the Vertebrates have certainly not descended from 

 the Articulated-animals {Arihvopoda), the Soft-bodied 

 Animals (MoUusca), or Star-animals (Echinoderma). There- 

 fore by far the greater part of the animal kingdom may be 

 entirely overlooked in our future investigations, whether 

 Ontogenetic or Phylogenetic. We have nothing further to 

 do with these. The three groups which alone interest us, 

 are the Primitive Animals (Protozoa), the W^orms, and the 

 Vertebrates. 



Those people who regard the descent of Man from the 



animal kingdom as a more or less degrading stigma, and 



are ashamed of it, may take such consolation as they can 



from the fact that the greater part of the animal kingdom 



is not akin to them. The Vertebrates have no connection 



with the great group of Articulated-animals (Arthropoda) ; 



bat to the latter belong not only the Crabs, but also the 



Spiders and Insects, which last form a single class, com- 



13 



