NEW INTERPRETATION OF CNIDARIA 293 



have become in this way their only representatives, do not 

 develop into true hermaphrodites ; they reproduce parth- 

 enogenetically having become unable to reproduce by means 

 of division or of budding. 



The consequences of the total internalization of gynogam- 

 etes (which are changed into karyons) — which forms the main 

 difference between the genuine Infusoria and the Eumetazoa— 

 have been radical and remarkable. We must therefore call 

 special attention to them. They had clearly evolved only after 

 the lines of evolution of the Infusoria and of the Eumetazoa 

 had become separated. In opposition to the conditions that 

 can be observed in the Eumetazoa where not only the andro- 

 gametes but also the gynogametes as such or even mature 

 embryos which have developed into young forms leave the 

 maternal body, we find in the Infusoria that their gynogametes 

 remain in the maternal body, their cytoplasms merge with the 

 cytoplasm of the maternal body without any distinct line left 

 between the two. This phenomenon can be observed in the 

 Infusoria only. The zygote is preserved even after complet- 

 ed insemination and fertilization, and the Anlagen of the 

 prospective infantile individual which had developed by w^ay 

 of divisions, are now merged in the maternal body by means 

 of the cytoplasm; in this way the maternal organism is not 

 only rejuvenated (reorganized), it becomes almost eternal; the 

 maternal form does not die, it continues its existence even 

 if it suffers a partial death due to the loss of its macronucleus. 

 The final result is a new complex animal which consists of 

 the maternal and infantile parts that constitute its whole 

 nuclear apparatus as well as parts of its cytoplasm. Thus it 

 is not the maternal organism which continues to exist here 

 as a whole; we rather have, in effect, a double being, while 

 at the same time there is also no real corpse. These unusual 

 conditions have become possible only in combination with 

 an extreme reduction of karyons. 



The evolution of the Eumetazoa has pursued an entirely 

 different direction. The gametes of the two sexes have remained 

 20 



