STRUCTURE, ETC., OF PLEISTOPHORA PERIPLANETH. 621 
16 to 18, 36), while the protoplasm aggregates itself around 
each nucleus, the trophozoite dividing finally into a number 
of spores (fig. 19). A process similar to this has been 
observed by Doflein in the case of Glugea lophii. It isa 
method of reproduction which, in Pleistophora peri- 
planete, strongly recalls the schizogony of the Telosporidia, 
e. g. the breaking up of the malarial parasite into a number 
of small sporozoites within the red blood-corpuscle. 
(3) A multinucleate trophozoite may divide into two by a 
process of simple fission (fig. 11). 
(4) Portions of a large multinucleate trophozoite may 
separate themselves from the parent cell and commence an 
independent existence (figs. 13, 20,55). The piece budded 
off may have one or several nuclei, and it seems that the 
buds are all either uninucleate or multinucleate exclusively 
(figs. 13 and 20), a trophozoite never apparently producing 
buds with one and many nuclei at the same time. A similar 
process to the above, of a multinucleate cell breaking up into 
multinucleate fragments, has been styled plasmotomy by 
Doflein. Division of the trophozoite into two fragments 
he calls simple; division into more than two fragments, 
multiple plasmotomy. The production of uninucleated swarm 
spores from a trophozoite by budding does not appear to 
have been hitherto recorded among the Myxosporidia. It is 
a noteworthy fact that no dark purple nuclei are to be found 
in trophozoites undergoing the above processes of reproduc- 
tion, and it seems likely, more particularly in view of the 
absence of pseudopodia, that the trophozoites containing 
these nuclei are about to form resting spores. This point 
will be referred to later (page 622). 
Spore ForMATION. 
All the above methods of reproduction subserve auto- 
infection, but resting spores are also produced which bring 
about the infection of fresh hosts. These resting spores 
