OF EVOLUTION. 5 i 







and less cat-like, and they can be traced down to 

 animals which on the one side link them to the 

 civets, and on the other, to the dogs. 



Again, the large group of the lemurs, those 

 singular representatives of the Quadrumana which 



impress such a distinct individuality upon the 





 fauna of Madagascar, become less and less lemur- 



ine the farther back we trace them, approximating 

 very closely to the type of insectivore structure. 

 So complete is this approximation that the most 

 experienced zoologists are at a loss to determine 

 in many cases whether certain ancient types are 

 in reality lemurs or insectivores. Other animal 

 groups likewise converge toward this same group 

 of the Insectivora, which (or certain immediate 

 allies) are now considered to represent the stem 

 from which most of the existing placental mam- 

 mals have been developed. We thus see how 

 unstable are the characters which have been 

 formulated toward the proper delimitation of ani- 

 mal groups. The beautiful classification of Cuvier, 

 which was founded on the assumption that the 



