278 
The Ohio Naturalist. 
[Vol. VIII, No. 5, 
may favor, with the hope of correlating the cytology of Synchvt- 
rium with that of other plants and animals, in a way which mav 
throw some light on some general problems of cell organization 
and finally to arrive at some conclusions regarding the relation¬ 
ships of the Chytridiales. 
Observations.* 
After the division of the primary nucleus of Synchytrium decip- 
iens which species alone was used in the present investigation, 
the secondary nuclei divide rapidly without the formation of cell 
walls till segmentation takes place when there are usually 500- 
800 nuclei in the cyst. Ivusano reports that all these mitoses 
are similar in S. puerariae and such seems to be the case in S. 
decipiens, the only change being in the continual diminution in 
the size of the nucleus. But while it is believed that all of the 
mitoses are similar it must be remarked that all of the observa¬ 
tions here presented, were made on cysts about midway between 
the primary cell and the segmented sorus in respect to the num¬ 
ber of nuclei, i. e., from cysts with 100-300 nuclei. Whether 
this has any significance or not we do not at present know. 
The spindles of Synchytrium like those of fungi generally, 
arise within the nucleus and reach metaphase before the nuclear 
membrane is dissolved from around them. As Stevens found 
both in the primary mitosis and in the succeeding ones, no cen- 
trosomes are demonstrable at the poles. The figure made by the 
separated chromosomes at each pole in anaphase (fig. 1) resem¬ 
bles greativ that of the same stage in the primary division, com¬ 
pare Stevens’s (03) fig. 13 with my fig. 1, thus strengthening the 
statement that all the mitoses are similar. There appear to be 
four chromosomes as Stevens supposed though it is sometimes 
difficult to see more than three (cf. figs. 1, 2, 8. In figure 1 there 
are four chromosomes at the pole wffiere only three can be seen, 
one being directly beneath the one showm nearest the nucleolus.) 
By the beginning of the telophase the daughter nuclei are 
separated by an unusually great distance from each other. In 
the mitoses from which the present figures were drawn they are 
about 20 microns apart (see figs. 1 and 12.) Such a condition as 
is shown in figure 5 where the daughter nuclei lie close together is 
quite unusual. It is readily seen that in thin sections the 
* Since the observations herein recorded were made but before they 
were embodied in their present form Kusano (07) has published a prelim¬ 
inary paperon Synchytrium puerariae in which he announces the same rela¬ 
tion ot the centrosomes to the nuclear membrane as is herein described. 
Though he gives five figures they are hardly sufficient to demonstrate his 
point and his fuller paper is to be much desired inasmuch as the action of 
the centrosomes of Synchytrium are so unusual that confirmation of the 
results by independent workers will undoubtedly be welcomed by the 
cytological fraternity. 
