180 CHARLES DARWIN. 



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thing. There is no real break between the genera- 

 tions ; they are thrown up successively from a contin- 

 uous line of germ-plasm. In this hypothesis the germ 

 is the essential thing, the body a mere secondary pro- 

 duct. It is a theory of Blastogenesis as contrasted 

 with Pangenesis. The hereditary transmission of ac- 

 quired characters, in which many still believe, is quite 

 irreconcilable with it, and if substantiated would over- 

 throw it altogether. 



On the other hand the body-cells are the essential 

 elements of pangenesis, and the germ-cells the mere 

 meeting-places of their representatives and quite 

 devoid of significance on their own account. There 

 is some sort of interruption between successive 

 generations, as the gemmules develop into cells, 

 which again throw oft' gemmules ; the break, how- 

 ever, is bridged by the ancestral gemmules and by 

 the life of the body-cell which intervenes between 

 the gemmule from which it arose and that to which 

 it gives rise. 



The remaining chief occasions on which Darwin 

 alludes to pangenesis in his published letters are 

 quoted below ; they prove his confidence in the 

 hypothesis and the nature of the hold it had upon his 

 mind. 



Later on he again wrote to Huxley on the same 

 subject : — 



" I am rather ashamed of the whole affair, but not converted 

 to a no-belief. . . . It is all rubbish to speculate as I have 

 done ; yet, if I ever have strength to publish my next book, T 



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