NOTES ON SOME PARASITIC PROTISTS. 129 
very distinct. In the middle of the cell which is about to 
divide a transverse septum makes its appearance, staining 
strongly with Giemsa or iron-hematoxylin. The ends of the 
organism also stain darkly at all stages of its life; this 
staining of the ends and of the septum being a common 
condition in bacteria. At this stage the organism has the 
appearance shown in fig. 20b. Later the septum splits into 
two, and its halves then give rise to the ends of the daughter- 
cells (fig. 20c). These then separate. 
Although this Bacillus resembles B. maximus buccalis 
in possessing a spirally disposed nuclear filament, it differs 
from it in its method of division. For in the latter a 
longitudinal splitting of the filament appears to take place, 
whereas in the former, as I have just shown, a transverse 
division can be seen. Swellengrebel’s very careful micro- 
chemical investigation of B. maximus buccalis renders it 
highly probable that the filament consists of a substance 
which, if not chromatin, is at least very closely allied to it. 
In my Bacillus I have seen no separation of ‘‘ chromosomes ”’ 
and achromatic substance during division. 
As this Bacillus does not appear to have been described 
before, | have named it Bacillus spirogyra, n.sp., from 
the fanciful resemblance which it bears to a Spirogyra cell 
with its contained chloroplast. 
I have not yet succeeded in tracing out the rest of its life- 
history. 
III. Spirillum monospora, n. sp. (PI1.6, figs. 21a, b, ¢, d.) 
A large species of Spirillum is not unfrequently found in 
the large intestine of frogs and toads. As I can find no 
record of it in the work of other investigators, I have called 
it Sp. monospora, n. sp., from the fact that it forms a single 
large terminal spore. 
This Spirillum is usually S-shaped. Its dimensions are 
ca. 6—8y xca. 15. It is actively motile, and can be seen 
(in deeply stained iron-hematoxylin preparations) to possess 
