BONNET'S THEORY OF EVOLUTION. 233 



ranted in assuming that they came into existence at a stage in 

 the evolution of the cosmos when conditions were somewhat 

 different from those now obtaining, and that they came by the 

 same great highway by which all things come and go — the 

 highway of natural law. 



Observe how complete the revolution in ideas. The old 

 preformation affirmed syngenesis and denied epigenesis ; the 

 new preformation affirms epigenesis and denies syngenesis. I 

 do not assert that the present idea of preformation affirms all 

 the extravagances that have usurped the name epigenesis ; but 

 I do claim that, as now generally understood, it denies the 

 very thing it formerly stood for, syngenesis, and presupposes 

 and advocates the very thing it formerly opposed, generation 

 in the sense of epigenesis. Not only is postformation, which 

 is all there is left of the old epigenesis, maintained, but it is 

 claimed to take place both from within and without. ^ 



More than that, everything that preformation now stands 

 for is regarded as the product of phyletic generation — as the 

 heritage of all past epigenesis. 



Is it strange that preformation now rests on the very princi- 

 ples it was originally supposed to exclude } No stranger cer- 

 tainly than that the old evolution should die as an idea and 

 live as a name for the antithetical idea of epigenesis. Such 

 changes are not rare, and when comparing the doctrines of 

 development in the eighteenth century with those of to-day, 

 we have to be on guard against concluding from identity of 

 names to identity of ideas. If names could be relied upon for 

 the identification of ideas, it would be easy to make Bonnet 

 the father of the dominant ideas of modern evolution. Bonnet 

 held to continuity in the scale of life, but how different is con- 

 tinuity in grades from continuity in generation of organisms .-' 

 Bonnet uses the expression ^'genealogical tree" to describe a 

 branching community of polyps. But would any one accuse 

 modern phylogenists, who make use of the same expression, of 



^ The present idea of preformation opposes only that one-sided epigenesis that 

 has lately come into vogue, which insists that all true epigenesis is from without, 

 and that all generation from within must bear the name " evolution." That is an 

 important distinction, setting off the extreme Lamarckian school, but it is mod- 

 ern and not essential to the idea of true generation. 



