SPIROCHHTA BALBIANII AND SPIROCHATA ANODONTA. 47 
concomitant nuclear changes already noted, longitudinal 
fission of the organism would result. Hlectrical charges 
induced by the movements of the chromidia would bring about 
such increase of “ tone.” 
Attempts at loosening the helicoid spiral of chromatin of a 
Spirochete, as during such a period of activity as division, 
would cause the bars or rodlets of the resting phase to become 
dumb-bell shaped, that is, the chromidia would concentrate 
at the periphery and the rodlets, after becoming dumb-bell 
shaped, would ultimately break across the centre. 
If, then, the flow of protoplasm is towards the periphery, 
that is, in the direction of the path of the chromidia and away 
from the centre of the organism, fission would be rendered 
still more easy. (Witness slight thickening of myonemes, 
shown rather faintly [Pl. 1, fig. 2].) 
Note on Potymorruism, Consucation, EncysrMent. 
It is necessary, I think, to consider these matters, more 
especially from.the point of view of completeness, for there 
is little evidence, at any rate at present, to support the exist- 
ence of these processes in Spirocheetes. 
Sexual Polymorphism.—Perrin (8, 9) in his account 
of 8. balbianii differentiates between “male,” “female,” 
and “indifferent” forms on certain morphological grounds, 
but “chiefly by their behaviour under adverse conditions ” 
(9, p. 135). This basis of differentiation is, it seems to me, 
unsound, for under such conditions one is probably dealing 
with abnormal forms. I fear too much systematic work 
already, perhaps, has been based on pathological specimens. 
Perrin himself states (9, p. 157) that :—‘‘ The morpho- 
logical differences between the two forms [indifferent and 
female] are thus small, and, unless . . . . the features [large- 
ness and stoutness] are sharply marked, it is by no means 
always easy to tell whether a given individual belongs to the 
female or to the indifferent type.” 
The “ working hypothesis” of sexual polymorphism, as set 
