54 H. B. FANTHAM. 
(c) The absence of a blepharoplast in the form in which it 
occurs in a T'rypanosome. 
Affinities with the Protozoa. 
As characteristics favouring their inclusion among the 
Protozoa we may note— 
(a) The possession of a membrane. 
(b) The occurrence of longitudinal fission. 
(c) They are implasmolysable. 
(d) Bacteriologists with whom I have conversed attach 
importance to what they consider the definiteness of the 
nucleus in these forms compared with the condition of the 
nucleus (or its seeming absence) in many Bacteria. Un- 
doubtedly chromatin masses occur (‘‘chromosomes” of 
Perrin) together with an achromatic thread. But there is 
probably chromatin present in the form of scattered chro- 
midia in all Bacteria. 
(ec) Bacteriologists also comment on the large size of S. 
balbianii but S. anodonteze is much smaller, while a 
species ike S. obermeieri is smaller still. Little importance 
is to be attached to size. 
(f) The presence of a small amount of a probably chiti- 
noid substance in the periplast and membrane. “Chitin” is 
an animal product, but I do not think it is present to any 
great extent, and only in a diffuse condition, for the body of 
Spirocheetes is very flexible—and there are probably several 
kinds of chitin. 
(g) The inability, up to the present, to find suitable artificial 
(bacteriological) media in which the Spirochestes may be kept 
alive. 
Longitudinal fission, I believe, is known among the Bacteria 
in Pasteuria ramosa and Bacillus maximus—also pro- 
bably in the case of the diphtheria bacillus. 
It has been stated (12) that 8S. duttoni is a Brareaen 
because regular recurrent relapses of tick fever result from 
its presence in the system. But apparently relapses may 
result from diseases due to Bacteria, as in typhoid or pneu- 
