466 
Spirochaeta gallinarum 
of coccoid forms (? spores), in the manner described by Balfour (1911) 
for this species, and also by Bosanquet (1911) for S. anodontae. I can 
entirely confirm Balfour’s description of this interesting process, which 
takes place at the crisis of the disease or after drug treatment. 
It is observed much more frequently in the contents of the gut of an 
Argas, which has previously fed upon an infected bird. The spirochaete 
gradually assumes the appearance of a chain of beads (Fig. 2 a-d) 
contained within the transparent cell-wall. 
After swimming about for some time in this form, the spirochaete 
appears to rupture at one end and the coccoid bodies escape into the 
surrounding medium, leaving an empty sheath behind them (e). In 
Fig. 2 a-f. Successive stages in the formation of the coccoid bodies 
(diagrammatic). 
some cases the whole cell-wall seems to disintegrate before the coccoid 
bodies escape, but the final result is the same, viz. the liberation of a 
varying number of minute round or ovoid bodies (/). 
The fact that these coccoid forms are produced in large numbers 
after drug treatment, or when the parasites are in unfavourable 
conditions, has caused them to be regarded previously as merely the 
result of granular disintegration. Apart from their regularity in size 
and appearance, which in itself precludes the possibility of their being 
regarded as degeneration products, the time of their appearance is just 
when one Avould expect them. Moreover, the appearance of degenerating 
spirochaetes is very different from that presented by segmenting forms, 
as, instead of the production of a row of coccoid forms of uniform 
thickness, either the whole spirochaete gradually dissolves away, or, as 
