YELLOW FEVER EXPEDITION 
563 
we could not obtain uninfected toads for trial of experimental infections. Further 
details may be forthcoming from the examination of the prepared material, which is 
to be examined. The suggestion is that the depranidium form is the gamete which 
completes its development in the arachnoid host, whilst the dactylosoma is the 
endocorporeal permanent parasite of the toad, they were not seen to leave the 
corpuscle in material either from tick or toad. 
An observation which may be of interest in the economy of tickborne diseases, 
for instance, in Texas cattle fever in which the young ticks are capable of carrying the 
infecting agent, is that a tick which had been left in a box laid eggs which had hatched 
out during my illness. The young ticks had eaten nearly all of the contained blood 
and organs of their mother. If the tick stages of a parasite (as drepanidium in this case) 
were alive in the mother, this would form a ready mode of securing the continuity of the 
existence of the parasite ; this would be especially important for the parasite in the case of a 
tickborne disease, for ticks usually remain upon a single host, and therefore would not be 
calculated to spread a disease from animal to animal. 
C. A. Trypanosome 
A small bat (Phy Ho stoma) which could not be examined at once was placed in a 
gauze cage, and with it a specimen of S. fasciata. The next day the bat was dead and 
the mosquito full of fresh blood. This blood contained abundant trypanosomes, whose 
shape is quite different from the usual ones in rats, Nagana, etc. Too much post- 
mortem change had occurred in the bat for satisfactory examination, but there were 
some structures which suggested altered trypanosomes ; one knows from Nagana how 
soon after death of the host changes ensue in the trypanosomes. Other bats were 
obtained but there was never leisure to examine them until death had occurred. 
Although often flagellates, coccidia like bodies, etc., were found from time to time in 
the eighty mosquitoes which were dissected, this was the only time that trypanosomes 
were found. 
Other Animals 
Blood examinations were made on a number of different animals. Only one out 
of about a dozen lizards (green ones and brown ones) showed endo-globular parasites. 
One small brown bird of the pigeon tribe was found full of Halteridium. A toucan 
and an agouti were negative. 
In the island of Marajo, about the cattle ranches, horses, dogs, etc., are said to 
suffer from a disease, consisting of wasting and paralytic symptoms, called ' quebra 
brunda.' It occurs during the dry season, and by local repute the capibara {capybarus) 
are said to sicken when or before the disease is prevalent. We saw many cattle with 
abundant ticks ; these were in a meagre and wasted state of health. 
