472 
Spwocliaeta gallinarum 
days, the parasites naturally make their way from this medium into all 
the organs, where they may easily be found. 
The development of the coccoid bodies was also followed in the eggs 
laid by infected Argas. It was found that the eggs usually contain a 
considerable number of these coccoid bodies and as in this case there is 
absolutely no possibility of external contamination, many were kept at 
a temperature of 37'" C. in order to follow the development of the 
spirochaetes. This was all the more important as the only experiments 
with the larvae hatched from the eggs laid by an infected Argas, seemed 
to show that the infection was not transmitted to the larvae. Blanc 
(1911) has used this as an argument against the view so ably put 
forward by Leishman (1910) that the granules (= coccoid bodies) 
represent a stage in the life-history of the spirochaete. 
Fig. 5. Cell from the embryonic Malpighian tubule of an egg that has been heated for 
5 days at 37° C. Showing the elongation of the intracellular coccoid bodies resulting 
in the production of long filaments. 
It was found, however, that not only could spirochaetes be obtained 
by maintaining the eggs containing coccoid bodies at a temperature 
of 37° C., but that also infection could be produced by feeding the 
infected larvae on a fowl. A large number of larvae, hatched from eggs 
laid by infected Argas from Algeria, were placed on a fowl. The bird 
showed parasites four days later and the next day died from the 
infection, with its blood swarming with spirochaetes. Another batch 
of larvae hatched from the eggs of the Argas from Brazil, but possibly 
mixed with some of the Algerian strain, also produced a fatal infection in 
