W. M. Aders 
203 
very conspicuous. The whole of the abdominal organs are in close 
relation to the fat bodies and tracheal tubes. Seven out of 120 adults 
were found to be infected ; many nymphs were examined but always 
with a negative result. 
Methods. 
The intestinal tract was removed and placed in a watch glass con¬ 
taining normal saline solution, a small piece of the crop was cut away 
and the conteuts placed on a slide and examined. In many cases 
swarms of herpetomonads were seen actively swimming about. Other 
pieces of the crop were now taken and their contents smeared out for 
staining. The films thus obtained were fixed in osmic acid vapour for 
a few seconds and then placed for ten minutes in absolute alcohol. I 
found Leishman’s stain the best to use, as with Gietnsa’s it was very 
difficult to stain the flagella satisfactorily. 
Structure and Life-Cycle of the Parasite. 
I shall commence by describing what I regard as the resting stage 
of the parasite. Bodies probably representing this stage were often 
found in the crop and on two occasions in the faeces. They are oval, 
