92 Hypothesis of Structure of Germ Substance 



different species the result of the graft is not certain 

 and often unfavorable. 



This can be explained by the fact that in numerous 

 species of plants, as we have seen, nearly all the cells 

 preserve the reproductive capacity. What one calls 

 "vegetative affinity" is then perhaps nothing else than 

 a direct effect of the retention of the whole of the 

 specific germinal potential elements in addition to the 

 somatic elements peculiar to each of the different tissues, 

 in all or nearly all the different nuclei which do not 

 pass beyond a certain degree of differentiation. 



In drawing a conclusion from all that has been said 

 so far, we are confronted with this apparent paradox: 

 on the one side, it seems that in conformity with the 

 epigenesists we must reject a nuclear division which 

 during one and the same development must be 

 sometimes qualitatively equal, sometimes unequal, as 

 inadmissable and refuted by the facts, and instead of 

 this admit only a nuclear division always qualitatively 

 equal. On the other hand it appears that in conformity 

 with the preformists, one must likewise exclude a nuclear 

 substance, identical in all the cells of the same organism, 

 and must accept on the contrary, the hypothesis of an 

 actual nuclear somatization. It follows that this nuclear 

 somatization can be effected only gradually and only by 

 a process of epigenetic nature. 



But when one has once admitted equal nuclear divis- 

 ion and gradual nuclear somatization by a process of 

 epigenetic nature, there follows therefrom necessarily the 

 hypothesis of centroepigenesis. For if the nuclei of the 

 cells of the different tissues of the body finally become 

 completely somatized it is certain that some certain ones 

 of the nuclei constituting the organism do not become 



