IX 



THE HISTOllY AND SCOPE OF ZOOLOGY 



345 



logie and the Schd2)fungsgesch{chte. Haeckel himself, 

 with his pupil Miklucho-Maclay, had in the meantime 

 made studies on the growth from the egg of Sponges, 

 — studies which resulted in the complete separation of 

 the unicellular or equicellular Protozoa from the 

 Sponges, hitherto confounded with them. It is this 

 introduction of the consideration of cell- structure and 

 cell-development which, subsequently to the estab- 

 lishment of Darwinism, has most profoundly modified 

 the views of systematists, and has led in conjunction 

 with the genealogical doctrine to the greatest activity 

 in research, — an activity which culminated in the 

 work (1873-1882) of F. M. Balfour, and produced the 

 profoundest modifications in classification. 



Haeckel's earlier pedigree is worth comparing with 

 his second effort, as showing the beginning of the influ- 

 ence just noted. The second pedigree is as follows : — 



