228 A Myxosporidian 
ohlmacheri, the two nuclei, as before stated, are usually of similar size, but 
assume soon afterward strikingly different aspects. 
Formation of trinucleate trophozoites similar to that described above, 
was observed in Sinuolinea dimorpha (Davis, 1916), and Ceratomyxa coris 
(Georgevitch, 1917a). Stempell (1919), however, believes that the trinucleate 
trophozoite of Ceratomyxa ( Leptotheca ) coris is formed directly from a uni¬ 
nucleate form by a heteropolar nuclear division. This controversy, arising 
from the observations of Georgevitch and Stempell on apparently one and the 
same species, is beyond my understanding. But in L. ohlmacheri, I have not 
seen a single instance which might suggest the occurrence of the process 
described by Stempell in the above-mentioned species. 
Concerning the relative number of trophozoites with one, two and three 
nuclei respectively in the infected host organs, Georgevitch (1917a) and Stem¬ 
pell (1919) noticed that the number of trinucleate trophozoites of Ceratomyxa 
coris, were much greater than any other stages. In this connection, George¬ 
vitch states that ‘'ce stade assez frequent dans nos preparations indique un 
stade de repos.” On the other hand, Stempell attributes the reason to the 
above quoted heteropolar division of the nucleus of the uninucleate form. 
In L. ohlmacheri, the number of trinucleate trophozoites is far greater 
than that of uninucleate or binucleate forms. In my opinion, this is due to the 
following two reasons. In the first place, this stage is most probably one of 
growth. As was noted in every one of the infected kidneys, the body of the 
trophozoites at this stage varies greatly in size which is reasonably explained 
by regarding it as a growth stage. Secondly, as will be stated later, young 
trinucleate trophozoites are constantly produced by the process of gemmation 
in the later stage. 
The karyosome in the vegetative nucleus of a trinucleate trophozoite is 
frequently divided into two (Fig. 33), one of which remains in the vegetative 
nucleus. This gives rise to another generative nucleus (Fig. 34) which divides 
into two (Figs. 35, 36). At the same time, these become surrounded by more 
deeply staining cytoplasm, and separated from the main part of the cyto¬ 
plasm by a clear space. One of the nuclei, becomes the vegetative nucleus, 
while the other divides once more, thus forming a trinucleate form, with one 
vegetative and two generative nuclei. The trinucleate body is extruded 
from the mother trophozoite. I have repeatedly seen gemmation in hanging 
drop preparations, the time needed for the completion of the process 
varying from 30 minutes to 3 hours at 20° to 25° C. The extrusion may in 
some cases be much delayed (Figs. 39, 40). The liberated trinucleate stage is 
essentially the same in the nature of the nucleus with that of the mother 
trophozoite, mainly differing in size of the body (Figs. 37-40). The body of 
the gemma now grows and repeats the same process. One gemma is formed 
in a trophozoite at one time. Whether or not one individual undergoes 
repeated gemmation cannot definitely be stated. But judging from the large 
number of the trinucleate stage present in every case, I am inclined to think 
