Statement of Weismanris System (1886). 3 



ova and spermatozoa being thus aggregated packets 

 of gemmules, which have emanated from all the cells 

 of all the tissues of the organism. 



4. That the development of a new organism, out of 

 the fusion of two such packets of gemmules, is due to 

 a summation of all the developments of some of the 

 gemmules which these two packets contain. 



5. That a large proportional number of the gem- 

 mules in each packet, however, fail to develop, and 

 are then transmitted in a dormant state to future 

 generations, in any of which they may be developed 

 subsequently — thus giving rise to the phenomena of 

 reversion or atavism. 



6. That in all cases the development of gemmules 

 into the form of their parent cells depends on their 

 suitable union with other partially developed gem- 

 mules, which precede them in the regular course of 

 growth. 



7. That gemmules are thrown off by all physio- 

 logical cells, not only during the adult state of the 

 organism, but during all stages of its development. 

 Or, in other words, that the production of these cell- 

 seeds depends upon the adult condition of parent cells : 

 not upon that of the multicellular organism as a 

 whole. 



At first sight it may well appear that we have 

 here a very formidable array of assumptions. But 

 Darwin ably argues in favour of each of them by 

 pointing to well-known analogies, drawn from the 

 vital processes of living cells both in the protozoa 

 and metazoa. For example, it is already a well- 

 recognized doctrine of physiology that each cell of 

 a metazoon, or multicellular organism, though to 



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