NATURAL SELECTION, ETC. 109 



What more than this could be said for such an 

 hypothesis? Here, probably, is its charm, and its 

 strong hold upon the speculative mind. Unproven 

 though it be, and cumbered prima facie with cumula- 

 tive improbabilities as it proceeds, yet it singularly 

 accords with great classes of facts otherwise insulated 

 and enigmatic, and explains many things which are 

 thus far utterly inexplicable upon any other scientific 

 assumption. 



We have said that Darwin's hypothesis is the natu- 

 ral complement to Lyell's uniformitarian theory in 

 physical geology. It is for the organic world what that 

 is for the inorganic ; and the accepters of the latter 

 stand in a position from which to regard the former in 

 the most favorable light. Wherefore the rumor that 

 the cautions Lyell himself has adopted the Darwinian 

 hypothesis need not surprise us. The two views are 

 made for each other, and, like the two counterpart pic- 

 tures for the stereoscope, when brought together, com- 

 bine into one apparently solid whole. 



If we allow, with Pictet, that Darwin's theory 

 will very well serve for all that concerns the present 

 epoch of the world's history — an epoch in which 

 this renowned paleontologist includes the diluvial or 

 quaternary period — then Darwin's first and foremost 

 need in his onward course is a practicable road from 

 this into and through the tertiary period, the interven- 

 ing region between the comparatively near and the 

 far remote past. Here Lyell's doctrine paves the way, 

 by showing that in the physical geology there is no 

 general or absolute break between the two, probably 

 no greater between the latest tertiary and the quater- 



