14 
which distinguishes the male elements (microgametes) from the female 
(macrogametes) . 
The method of inoculation of a dog ^vith L. cams by the tick is 
imknown. Christophers states that since the female tick does not 
suck blood again after repletion, the passage of the sporozoite into 
the ova seems a necessity if the parasite is to regain entrance into the 
mammalian host. He has been unable to find sporozoites in the ova 
or. in fact, anywhere except in the gut of the ticks. 
Adie,® in India, has observed in blood smears from Mus rattus, in 
each instance accompanied by tr^-panosomes, a leucocytozoon vdth an 
oval nucleus and without cytocyst, and about one-third the length 
of the leucocyte in which it was inclosed. Fiu-ther details regarding 
it are lacking. 
Summary . — A critical examination of the literature dealing with 
the Hsmogregarinidfe reveals the fact that almost notliing is definitel}' 
known concerning their sexual cycle and manner of transmission. 
HEPATOZOOX PERXICIOSUM. 
Matekial axd Techxique. 
An examination of a blood smear from a wliite rat wliich had died 
from an unknovm cause revealed a large number of protozoan para- 
sites somewhat resembling Leucocytozoon canis. It was found upon 
inquiry that the stock of white rats kept Tor laboratory use, in cages, 
in a wooden building adjoining the stable was being greatly depleted 
by disease. Many of the animals became anaemic and emaciated and 
after a longer or shorter period, usually a week or more, died. Upon 
examination it was foimd that some of the cages were infested with 
mites, which were present in large numbers upon the rats. Some of 
these mites, taken from an infected rat, were found to harbor the 
leucocytic parasite found m the blood of the rats. A more extended 
study revealed the interesting fact that the sexual phase of the para- 
site occiu-s in the mite. 
Seventeen rats, four of wliich died later, were made the basis of a 
study of the parasite in the rat. In addition, a large amount of 
material was obtained from rats experimentally infected. Material 
in a perfectly fresh condition was taken from all organs and preserved 
in fixing fluids. All the customary fixatives were employed, but the 
most satisfactory reagent for preserving the parasites in tissues was 
found to be formalin (formalin = 40 per cent formaldehyde). In 
strengths of 4 to 10 per cent of formalin in normal salt solution the 
tissues were immersed for twenty-four hours, then washed out in 
water and preserved in 70 to SO per cent alcohol. Sections varying 
a Adie, J. E. : Aote on a leucocinozoon found in JIus rattus in the Punjaub. Joiim. 
trop. med., vol. 9, 1906. p. 325 
