350 SYDNEY J. HICKSUN. 



the meganucleus undergoes fragmentation at an earlier stage 

 than it does in Dendrocometes, and consequently any con- 

 jugation that takes place between meganuclear fragments 

 might be very easily overlooked. The fact that in his most 

 recent publication Prowazek figures (figs. 27 and 30) the 

 extension of a fragment of the meganucleus of one con- 

 jugating Stylonychia into the body of the other, supports the 

 suggestion that it may occur elsewhere. The second objection 

 is fatal to the view I am putting forward, if it is true, that the 

 meganucleus dies when it fragments. It is, however, really 

 of the nature of an assumption to say that the meganucleus 

 dies at the close of conjugation. 



Entz, Balbiani, Gruber, Maupas, Hoyer, and Prowazek are 

 agreed in the statement that the fragments of the meganucleus 

 are absorbed by the cytoplasm. In some species (Chile don 

 cucuUulus, Colpidium colpoda, etc.) the meganucleus 

 does not even fragment, it simply gradually diminishes in 

 volume and disappears. On the other hand, Biitschli (2, 

 p. 1617) is of opinion that in Colpidium and Stylonychia the 

 fragments of the meganucleus areejected by the anus after con- 

 jugation. Having very carefully examined the process in Den- 

 drocometes, and found no evidence of the rejection of any part 

 of the meganucleus during or after conjugation, I am disposed 

 to agree with those who believe that the old meganucleus is, 

 as a rule, absorbed by the protoplasm. It is quite possible, 

 however, that with the absorption of the greater part of the 

 meganucleus there may be a rejection, in some species, of the 

 remainder. 



T'he expression '' absorption " or " solution," as applied 

 to the meganucleus at this stage, is very liable to mislead. 

 We may hold the view that the meganucleoplasm is killed, 

 converted into some proteid food substance, and then assimi- 

 lated by the surrounding cytoplasm, and we may use the 

 word "absorption" to express this meaning. Or we may 

 hold the view that the meganucleoplasm becomes more fluid 

 in consistency, and is diffused in a chemically unaltered, or 

 very slightly altered, condition through the cytoplasm, and 



