Some Questions which they Suggest. 19 



The other method by which nuclei divide is a highly 

 complicated and remarkable process, known often by the 

 long name of Karyokinesis i.e., the movement of the 

 kernel. In this process certain polar bodies appear, round 

 which the constituents of the cell gather, and the nucleus 

 assumes a curious spindle-like shape before the division 

 actually occurs. 



Now, in the myxies, we have, as we know, no true cells 

 with cell walls, except, perhaps, in the spores themselves, 

 but we have protoplasts, in the form of swarm spores, pro- 

 vided with nuclei, as shown in Fig. 3. In the plasmodium, 

 too, we have nuclei, and it has been supposed that the 

 original number of nuclei in the plasmodium corresponded 

 with the number of the constituent protoplasts, but it has 

 been shown that the nuclei increase vastly in number, and 

 that this division and multiplication of nuclei takes place 

 in all the stages of the swarm cells, of the plasmodium and 

 of the sporangium. The question whether this multiplica- 

 tion of nuclei in the myxies at the various stages takes 

 place by simple division or by the complicated process of 

 Karyokinesis is one which has been carefully investigated, 

 although the results can hardly as yet be considered as 

 conclusive. They appear to be, first, that Karyokinesis 

 is the method pursued in the swarm spores when they 

 divide, and again at a later stage in the sporangium shortly 

 before the formation of spores; and, secondly, that the 

 multiplication of nuclei in the plasmodium is sometimes 

 accomplished by Karyokinesis, but probably, also, by direct 

 division. 



