DENDROCOMBTES PARADOXUS. 349 



possible, and the " onus proband! " really rests upon those 

 who maintain that two globules of protoplasm, such as these, 

 can remain in junction for twenty-four hours without becom- 

 ing intimately mixed. 



A third point of indirect evidence bearing upon this 

 question is afforded by the behaviour of the meganucleus of 

 Dendrocometes during conjugation. If we regard the 

 meganucleus as a somatic nucleus — that is to say, as a nucleus 

 which is functionally connected with all the vital functions 

 except the sexual functions of the body, and as a nucleus 

 therefore which controls or is controlled by the greater part 

 of the cytoplasm of an animal cell such as Dendrocometes is, — 

 then the presence of the meganuclei in the conjugative 

 processes during the interchange of the molecules of the 

 cytoplasm is not a matter for surprise. "Pourquoi, dira-t-on," 

 says fSaud, " les noyaux vont-ils se placer dans le pont qui 

 reunit les deux Stylocometes et les deux Dendrocometes ? 

 C'est peut-etre pour diriger les echanges et les mouvements 

 qui out lieu dans ce pont." I am prepared, however, to go 

 further than Sand, and regard the presence of the meganuclei 

 in the conjugative processes (le pont) not only as evidence 

 of their relation to the interchanges taking place in the 

 cytoplasm, but as evidence of the necessity of the inter- 

 change of molecules of the substance of the meganucleus 

 itself. During conjugation there is, in my opinion, a mixing 

 or a shuffling of the molecules of all the essential plasms of 

 the body, namely, of the micro-nucleoplasm, of the mega- 

 nucleoplasm, and of the cytoplasm. 



Concerning the conjugation of the meganuclear elements 

 two or three obvious objections appear. It might be urged 

 that the rarity of recorded observations of the fusion of the 

 meganuclei in the Heterokaryota, the disintegration of the 

 meganucleus during conjugation, and the origin of the new 

 meganucleus from the micronuclei, are facts which prove that 

 the junction of the meganuclei during conjugation in Dendro- 

 cometes is a matter of no essential importance. 



It may be pointed out that in the majority of the Ciliata 



