NOTES ON SOME PARASITIC PROTISTS. Dy 
been essentially the same in all cases, and merely confirm 
what can be seen in the living organism. 
I have encountered very many degenerate and plasmo- 
lysed forms of different kinds. Almost all of these have 
been nearly identical with similar conditions figured by 
Schaudinn in B. biitschlii. Indeed, his figures might easily 
stand for B. flexilis. I have found vacuolated forms, forms 
in which abnormal division into three is occurring, forms in 
which an abnormal formation of a single spore has taken or 
is taking place, etc., etc. I do not think it is worth while to 
describe these again in detail, but I may mention that I have 
also found involution forms which reached the enormous 
length of nearly 200 1, incompletely divided into as many as 
six cells, the whole chain writhing fitfully for hours, but 
owing to its unwieldy length unable to make any progress. 
Spore-formation in Bacillus flexilis resembles in a 
remarkable manner that of Bacillus bitschlii, as anyone 
who will take the trouble to compare my figures with those 
of Schaudinn can see. In both organisms the incomplete 
division into two daughter-cells is only temporary; it is 
followed by a re-arrangement of the granules into a spiral 
filament, and by the heaping up of the granules at the ends, 
two spores arise in a closely similar manner—a part of the 
spiral degenerating. 
Schaudinn, who discovered this remarkable process, looked 
upon it as a kind of primitive conjugation between daughter- 
cells, comparable to that which occurs in Actinospherium 
(R. Hertwig), and—as he himself showed later—in Ent- 
amceba coli. He was also able to demonstrate the exis- 
tence of a similar phenomenon in Bacillus sporonema, 
Schaudinn. I think the evidence is strongly in favour of 
such an interpretation. 
A striking analogy exists in the case of the yeasts, which 
have yielded such interesting results to recent investigators. 
It is now conclusively proved that in some genera—e. g. 
Schizosaccharomyces and Zygosaccharomyces— 
conjugation, followed by sporulation, takes place between 
