J. W. S. Maokik 
283 
and at first glance appeared to be without waves. A more careful 
examination showed that the waves were still there, and in the usual 
numbers, but that their amplitude was greatly reduced so that they 
were barely recognisable (see fig. I, 67-70). 
Structure. The ends of the spirochaetes were almost always pointed, 
but some were rather blunter, and occasionally an organism was seen 
with one end more pointed than the other. The latter form is explained 
by Fantham as the product of a recent division. 
The cytoplasm appeared to be homogeneous, and chromatin granules 
and rodlets occurred frequently at intervals along the body. A mem¬ 
brane or crest was seen in some of the spirochaetes quite clearly, but 
in the majority it could not be distinguished. One parasite with a 
double membrane was observed. The endoplasm in a few of the 
parasites was broken up into several pieces separated by narrow 
unstained intervals. 
In not a few of the spirochaetes the body contained a number 
of deeply stained round or oval bodies that appeared to have been 
formed by concentration of the cytoplasm. These were presumably 
coccoid bodies. Some of the parasites appeared to consist of coccoid 
bodies only enclosed within a periplastic sheath. 
Division. Whenever the spirochaetes were examined double 
forms (fig. I, 59-61) composed of two organisms united by a delicate 
filament were seen, and in a series of specimens it was possible to trace 
all stages between these forms and unattenuated individuals. In 
fresh preparations the separation of the central strand was observed 
to take place, two independent organisms resulting from this transverse 
fission. The process so far as it was observed resembled that described 
by Mackinnon (1909) for S. recurrentis rather than that described 
for S. gallinarum by Hindle (1911); although not infrequently parasites 
were seen doubled back and coiled round their own bodies (see fig. I, 
39-41), and one or two intertwined couples were observed (fig. I, 42) 
such as Hindle mentions as resulting from the spirochaete breaking 
in two before the daughter parasites have uncoiled from each other. 
On several occasions Y-shaped parasites were seen. The behaviour 
of these forms when alive has already been described. In stained 
preparations the united end did not show any indication of being 
composed of two spirochaetes twisted together and was quite distinct 
from the “incurved” forms, and I am therefore of the opinion that 
they represented a stage in longitudinal division. These forms were 
especially numerous in a 24 hour old culture made by adding some 
Parasitology ix 
19 
