332 
Oriental Sore 
in the gut contents, but in the method of smearing it is almost im¬ 
possible to be sure from where the various forms seen have originally 
come. In the case of the rat haemogregarine Miller has not noted any 
escape of the sporozoites from the sporocysts while they are still within 
the body of the mite. He has found, however, that when treated with the 
intestinal juice of rats the sporocysts rupture and the sporozoites escape. 
This led him to feed healthy rats on crushed mites containhrg sporocysts. 
In this way, and in this way alone, was he able to produce an infection 
in healthy rats. It is possible that in the dog also infection takes place 
in a similar manner, through the intestinal wall, by the dog eating the 
infected ticks. The sporozoites would then be liberated in the gut, 
make their way into the spleen or bone marrow, enter a mononuclear 
cell and develop into the schizonts producing about three large 
merozoites. The merozoites would escape and develop into those 
foims which produce the well-known haemogregarines found in the 
peripheral blood. Whether these are really gametes or gametocytes 
cannot be settled till the exact process of conjugation is known. 
According to Miller they must be regarded as gametes which conjugate 
in the intestine of the tick. 
The course of the development given above for the haemogregarine 
of the dog, as far as it is complete, agrees in almost every detail with 
that of Miller, for the similar parasite of the rat. I hope at a later 
date to be able to till in the gaps in this life history. 
IV. Flagellates of House-flies. 
As in many of the Eastern cities a large proportion of the Bagdad 
house-flies are found to harbour intestinal flagellates. Of these I have 
met with three types, but whether each type represents a distinct species 
of flagellate or three different stages of one and the same flagellate, 
I am not in a position to state. Two of these correspond with the 
flagellates described by Flu from the house-fly, and one is found chiefly 
in the malpighian tubes and is interesting in that it shows the trypano¬ 
some arrangement of nucleus and kinetonucleus. Of the two flagellates 
described by Flu one is the Herpetomonas muscae domesticae of 
Prowazek ; the other is spoken of by Flu as a Leptomonas. The chief 
object of the present account is to show that in the case of the former 
the description of Prowazek is probably based on a faulty interpretation 
of the appearance of the flagellate in division. Prowazek described his 
