18 
Bloofl Parasites 
determine whether trypanosomes, for example, passed any of their life 
history as intracorpuscular bodies. 
At least one thing was acquired by these examinations and that is 
some degree of efficiency in detecting new bodies foreign to normal 
blood. 
With regard to the methods used there is little to say. Films of 
blood obtained from the peripheral vessels, the heart and in some cases 
from the internal organs were in all cases immediately fixed with 
the vapour of 1 "/o osmic acid, and then allowed to dry. Drying 
was expedited by using slightly warm slides or by waving the films in 
the air. 
These were stained either by Leishman’s or, after fixation with 
absolute alcohol, with Giemsa’s stain. A few were first covered with 
Leishman’s solution for about a minute and then stained in the ordinary 
way with Giemsa. 
Latterly I found that Giemsa’s new rapid method gave by far the 
best results. The stock solution of Giemsa’s stain is diluted with equal 
volumes of Merck’s pure methylic alcohol and this is used very much like 
Leishman’s method, only very much more neutral distilled water was 
added. Parasites which stain indifferently with Giemsa’s stain used in 
the ordinary way after fixation with absolute alcohol, are extremely well 
stained by Giemsa’s new method. 
Preparations were invariably mounted in Parolein, as I (1911) have 
described elsewhere. In this medium the parasites are not liable to 
fade, and on account of the low refractive index and total absence of 
colour of Parolein, or liquid Paraffin, their minute structure is rendered 
more visible. 
TRYPANOSOMES. 
Trypanosomes, mature and immature of the Pipistrelle. 
I have examined the blood of 2.5 bats belonging to three species and 
have found the following parasites. 
Trypanosomes were present in three out of 20 common small bats 
or Pipistrelle (Vesperuyo pipistrellus), 13 of which came from Reading. 
The three infected Pipistrelles were amongst those kindly sent me by 
Mr Ed. and Miss Blatch of Reading, and I take this opportunity 
of expressing my thanks to them for their kindness in procuring those 
and other specimens. 
In one of these Pipistrelles the infection was severe and stages in 
development were seen (May 1906), in another (1913) the trypanosomes 
