m THE ORIGIN OF SPECIES 79 
_ Existence, on Instinct, on Hybridism, on the Imper- 
‘fection of the Geological Record, on Geographical 
‘Distribution, have not only no equals, but, so far 
as our knowledge goes, no competitors, within the 
range of biological literature. And viewed as a 
whole, we do not believe that, since the publica- 
tion of Von Baer’s “ Researches on Development,” 
thirty years ago, any work has appeared calculated 
to exert so large an influence, not only on the 
future of Biology, but in extending the domination 
of Science over regions of thought into which she 
_ has, as yet, isabdly penetrated. 
