100 ORGANIC EVOLUTION CONSIDERED 



or, at most, a very few generations will produce a 

 distinct species. This is supplemented by the theory 

 that the new species is born cross-sterile with the 

 parent species. These things being true, the absence 

 of connecting links is accounted for. 



The only difficulty about this is that it is founded 

 on two assumptions, both of which are destitute of 

 the support of facts. If sexually isolated species 

 have been thus generally produced, it is opposed to 

 the commonly accepted theory of evolutionists, who 

 hold Darwin's view of very slight changes. 



It seems, however, that Le Conte does not accept 

 his own theory that species have been suddenly 

 formed with but few connecting links, except in cases 

 like the hundreds of feet of continuous rock in the 

 fresh-water Tertiary, where he stands in pressing need 

 of such a theory to account for species which seem to 

 come as if "by substitution of one species for an- 

 other, and not by transmutation of one species into 

 another," for he also tells us* that Planorbis has 

 been evolved by slight changes which have been 

 traced out to the " subtilest gradations," but that the 

 changes in its evolution seem to have sometimes been 

 "somewhat paroxysmal." 



Without dwelling longer on this, it is evident that 

 evolutionists must, with Le Conte, deny the existence 

 of many intermediate forms between species, or, 

 admitting that many transitional forms have existed, 

 they must give some plausible theory explaining their 

 quite universal absence among fossils. Unless this is 

 done the theory fails. Their absence is a matter of 

 vital importance. 



It should be remembered that the geological record 

 contains nearly the whole of the tree of life, so that 

 if it "merits the name of a chapter of accidents," 



* Evolution, p. 238. 



