THE ORIGIN OF SPECIES 163 



of M. Pictet, from whose calculations of what percentage 

 of the genera of animals, existing in any formation, lived 

 during the preceding formation, it results that in no case 

 is the proportion less than one-third, or 33 per cent. It is 

 the triassic formation, or the commencement of the mesozoic 

 epoch, which has received the smallest inheritance from 

 preceding ages. The other formations not uncommonly 

 exhibit 60, 80, or even 94 per cent, of genera in common 

 with those whose remains are imbedded in their predecessor. 

 Not only is this true, but the subdivisions of each formation 

 exhibit new species characteristic of, and found only in, 

 them ; and, in many cases, as in the lias for example, 

 the separate beds of these subdivisions are distinguished 

 by well-marked and peculiar forms of life. A section, a 

 hundred feet thick, will exhibit, at different heights, a 

 dozen species of ammonite, none of which passes beyond 

 its particular zone of limestone, or clay, into the zone below 

 it or into that above it ; so that those who adopt the 

 doctrine of special creation must be prepared to admit, 

 that at intervals of time, corresponding with the thickness 

 of these beds, the Creator thought fit to interfere with the 

 natural course of events for the purpose of making a new 

 ammonite. It is not easy to transplant oneself into the 

 frame of mind of those who can accept such a conclusion 

 as this, on any evidence short of absolute demonstration ; 

 and it is difficult to see what is to be gained by so doing, 

 since, as we have said, it is obvious that such a view of the 

 origin of living brings is utterly opposed to the Hebrew 

 cosmogony. Deserving no aid from the powerful arm of 

 Bibliolatry, then, does the received form of the hypothesis 

 of special creation derive any support from science or sound 

 logic ? Assuredly not much. The arguments brought 

 forward in its favour all take one form : If species were not 

 sup era at ur ally created, we cannot understand the facts 

 x, or y, or z ; we cannot understand the structure of 

 animals or plants, unless we suppose they were contrived 

 for special ends ; we cannot understand the structure of 

 the eye, except by supposing it to have been made to see 

 with ; we cannot understand instincts, unless we suppose 

 animals to have been miraculously endowed with them. 



As a question of dialectics, it must be admitted that this 

 sort of reasoning is not very formidable to those who are 

 not to be frightened by consequences. It is an arg amentum 

 ad ignorantiam take this explanation or be ignorant. 



