180 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



certain fossil Dasycladese and fossil Diatoms from Tertiary 

 beds as materials for discussion. The theory of develop- 

 ment requires the supposition that we have in Algse the 

 least changed descendants of the earliest forms of life that 

 appeared on the globe, but the testimony of the rocks is 

 barren in this respect — nay it is worse than barren, since 

 it is difficult to account on this hypothesis for the absence 

 of Diatoms for example from the Silurian and other early 

 beds in which one might expect from the nature of the 

 deposit to find them or organisms of a like kind. It 

 would be easy to insist on the comparative worthlessness 

 of negative evidence in a case of this kind, but it is a duty 

 to state the difficulty emphatically if it is ever to be 

 removed. It is difficulties of this stubborn kind that stand 

 in the path of the theory of evolution and not the ingeni- 

 ously constructed and imaginary obstacles evolved from 

 the fermenting brains of the new school of subjective 

 naturalists who know not Darwin but who know Nature 

 well — at second hand. 



