38
by them as belonging to one species, while Laveran believes they represent separate
species on account of the variation in their size and appearance and in his classifi-
.cation of the Hæmocytozoa gives a list of eleven species.
In Madras I have found Hæmogregarines in the following snakes : —
Python morulus.
Eryx Johnii.
Naia tripudians.
Bungarus cœrulus.
Vipera
Trophidonotus stolatus.
Zameni.s mucosus.
Trophidonotus piscator.
Dryophis mycterizans.
Dendrophis pictus.
After studying many of these parasites I have been unable to .satisfy myself
that the slight variations in the size and appearance of the adult trophozoits are
of sufficient value to consider them distinct species. Their slight variations are
readily explained by the fact that in. many cases the trophozoits were not of the
same age, and before it is possible to settle the point it would be necessary to
compare them throughout their life cycles.
The rat snake Zamenis mucosus is very suitable for the study of the parasites as
over 90 per cent. are infected. In the blood of this snake three distinct forms are
seen as follows :—
(a) The trophozoit varying in. size up to a large parasite with a globular
head and well formed tail ; in fresh blood it is commonly seen as a vermicule which
travels freely in and out of the red cells.
(b) Encysted forms seen as kidney-shaped bodies which are difficult to stain
owing to the presence of a resistant cyst, but with prolonged immersion in Giemsa's
stain they show a compact central nucleus surrounded by blue protoplasm while
the two ends stain dark pink and suggest the extrusion of some part of the
. parasite during the process of encystment. The red cells containing their parasites
stain feebly and exhibit pink stippling.
(c) A globular form without a tail containing a large loose nucleus with
diffuse chromatic strands.
I have been unable to confirm Lutz's observations on the sexual dimorphism
of the schizonts ; this cycle which is well seen in the lung can be followed from
the earliest changes up to the ripe cysts containing from 20-30 merozoits. A
single parasite encysts and later the nucleus breaks up and diffuses itself through
the protoplasm which now become markedly vesicular and as a result of division
two parasites are seen in the cyst ; this process is repeated till the mature cyst is
formed.
On many of these snakes two species of ticks of the genus Aponomma are
found and it is most probable, in view of the discovery of the development of
L. canis in the dog tick, that the sporogenetic cycle will be found in one or other
o f t h e s e t i c k s .
Over 50 specimens of 8 species of Hydrophidœ were examined but no blood
parasites were found.
APPENDIX XV.
PARASITIC FLAGELLATA.
By the SUPERINTENDENT.
A species of herpetomonas has been found to be common in several species of
mosquito and can be easily traced through the larva and pupa of these. In the
larva infection is first evidenced by the appearance of globular forms attached to
the intestinal wall just beyond the pyloric constriction. These may cover this
portion of the alimentary canal appearing like a layer of epithelium, or they may
be present in small numbers only. In the adult they have become free and
elongated forms endowed with very active movements.