160 Darwin, and after Darwin. 



of a positive kind, instead of a mere absence of infor- 

 mation of any kind. But if the adverse argument 

 reaches only to the extent of maintaining that the 

 geological record does not furnish us with so com- 

 plete a series of " connecting links " as we might have 

 expected, then, I think, the argument is futile. Even 

 in the case of human histories, written with the inten- 

 tional purpose of conveying information, it is an 

 unsafe thing to infer the non-occurrence of an event 

 from a mere silence of the historian and this espe- 

 cially in matters of comparatively small detail, such 

 as would correspond (in the present analogy) to the 

 occurrence of species and genera as connecting links. 

 And, of course, if the history had only come down to 

 us in fragments, no one would attach any importance 

 at all to what might have been only the apparent 

 silence of the historian. 



In view, then, of the unfortunate imperfection of 

 the geological record per se, as well as of the no less 

 unfortunate limitation of our means of reading even 

 so much of the record as has come down to us, I 

 conclude that this record can only be fairly used 

 in two ways. It may fairly be examined for 

 positive testimony against the theory of descent, or 

 for proof of the presence of organic remains of a 

 high order of development in a low level of strata. 

 And it may be fairly examined for negative 

 testimony, or for the absence of connecting links, 

 if the search be confined to the larger taxonomic 

 divisions of the fauna and flora of the world. The 

 more minute these divisions, the more restricted must 

 have been the areas of their origin, and hence the 

 less likelihood of their having been preserved in the 



