148 Autoiioiny of Cell-Organs 



phenomena, for up to the present time they have probably 

 not been utilized for the theory of heredity. But the more 

 plainly we see the independence of the individual organs 

 of the protoplasts, and the more clearly our conviction 

 grows that they require a high inner differentiation for 

 exercising their functions, the more will we be inclined 

 to give them their due place in our theory, and especially 

 will we try to investigate the more thoroughly their rela- 

 tion to the hereditary factors accumulated in the nucleus. 



Wherever, hitherto, we have succeeded in demonstrat- 

 ing with complete certainty the origination of trophoplasts, 

 we have found that they arise through a division of those 

 already present. That the chlorophyll grains, in the 

 higher plants as well as in the algae, can multiply through 

 constriction and scission has long been known. But it 

 was Schmitz who showed that this process is the only form 

 of their multiplication in the algae.^^ In the Characese he 

 discovered, in the apical cells, the colorless bodies from 

 which the green organs of these plants are derived in 

 the same way. These investigations are now so generally 

 known that it would be superfluous to describe them here 

 in detail. I shall only emphasize, as especially important, 

 the fact that the swarm-spores also possess only such 

 chromatophores as they have received from their mother- 

 cell, a fact that was especially mentioned in the case of 

 Cladophora and Halosphaera.^^ 



The investigations by Schimper and others, who dis- 

 covered this same law for the phanerogams, have already 

 been discussed in one of the preceding Chapters. 



Special consideration is still due to the rarer forms 

 derived from the more general chromatophores. In the 



s^Schmitz, Die Chromatophoren der Algen. 1882. 

 39Loc. cit. pp. 135, 136. 



