304 
A New Gregarine 
Spores. 
The ripe spores are highly refringent barrel-shaped bodies measuring about 
7/x by 3/z (Fig. 5 D and E). 
Effect of Gregarine on Host Cells. 
The presence of the gregarine seems to be more or less harmless since all 
the larvae and adult beetles appeared perfectly healthy although they have 
been reared for the last five years in the same jar and subject to continual 
infection. Possibly the greater part of the digestive processes of the larva 
takes place in the foremost part of the mesenteron in the lateral pouches. It 
is known that the yeasts take an important part in the digestion of the food, 
and the yeast infested cells are, as stated above, entirely free from the gre¬ 
garine. This might explain to some extent the ability of the larva to support 
such a heavy infection of the hinder portion of the midgut. 
The action of the gregarine on the cells of the intestinal epithelium is 
difficult to trace, possibly, however, like Pyxinia mobuszi inhabiting the 
alimentary canal of Anthrenus verhasci , it does not cause atrophy of the host 
cell. Leger and Duboscq suggest that in this species the epimerite stretches 
right through the epithelial cell in which it is imbedded, and piercing the 
basal layer of the cell, absorbs blood from the body cavity of the host 1 . 
Systematic Position. 
This gregarine may be assigned to the genus Pyxinia on account of the 
shape of its epimerite, and the character of its cysts and spores. 
It differs essentially from P. rubecula Hammerschmidt, P. crystalligera 
Frenzel, and P. bulbifera Watson, in the character of its epimerite, and in its 
much smaller size. 
It resembles in many respects P. frenzeli of Laveran and Mesnil and 
P. mobuszi of Leger and Duboscq, but certain characters preclude it from 
being assigned to either of these species. In P. anobii the epimerite is simple, 
whereas in P. frenzeli the epimerite is in two parts: a slender cylinder, and 
superimposed on the same a short apical style. The shape of the sporont also 
in the latter is obese, and the spores are much larger (14/x by 6p,). 
P. mobuszi possesses a simple epimerite, but this is relatively longer than 
in P. anobii. There is also a marked difference in size between these two species: 
the maximum length of the sporont of P. anobii is 250/x, and of P. mobuszi 
only 140/z. 
Acknowledgment: I am greatly indebted to Dr D. Keilin who placed the 
material for this investigation at my disposal and aided me with valuable 
suggestions. 
1 “On peut expliquer ainsi pourquoi Pyxinia mobuszi n’entraine pas d’atrophie. Sa longue 
trompe n’absorbant sans doute que le sang de l’Anthrene, n’enl&ve aucune nourriture a la cellule 
intestinale qu’elle traverse, et n’est pour elle qu’une inclusion presque inoffensive.'’ 
