324 07'ientcd Sore 
stages. There can be, however, no doubt that this is the vnode of 
infection. 
The whole course of this development bears a very close resem¬ 
blance to the development of Lankesteria ascicliae given by Siedlecki. 
It differs in that there is incomplete isogamy, as distinguished from 
complete isogamy, where both the size of the gametes and their nuclei 
are equal, the une(|ual size of the conjugating nuclei marking a differ¬ 
entiation into male and female gametes. In both cases the gregarines 
are intracellular during the greater part of their trophic period and 
they both have the same peculiar fixation organ. The resemblance is 
so close that both forms should be included in the same genus. The 
name for this gregarine of Stegomyia fasciata will then be Lankesteria 
culicis (Ross) 1898. I did not encounter gregarines in any other 
mosquito though these were taken from the same well in which were 
breeding the Stegomyia showing the largest percentage of infected 
individuals. 
III. Some Observations on the Development of the Haemo- 
GREGARINE OF THE LeUCOCVTES OF THE DoG. 
Occurrence of the infection. It has already been mentioned in the 
first section of this report that practically without exception, all the 
Bagdad street dogs are found to harbour this parasite. I was able to 
perform autopsies on one hundred and ten dogs of all ages and it was 
nearly always possible to find the developmental forms of this parasite 
in the spleen or bone marrow. Sometimes the infection was a small 
one and several preparations had to be searched in order to discover a 
single cyst. 
In other cases the infection was very large, so that numbers of cysts 
occurred in each squash preparation of either spleen or bone marrow. 
The cysts can readily be detected with a low power objective in simple 
squash preparations of the fresh organs. It seems that when once a 
dog is infected with this haeinogregarine it remains infected for the 
remainder of its life. It is probable that the duration of life of the 
dogs is not great owing to the fierce struggle for existence which these 
dogs have to endure in the Bagdad streets. The appearance of the 
haeinogregarine as it occurs in the dried blood films stained by any 
Roraanowsky stain calls for no remarks. It has already been fully 
described by several observers. In films fixed by methods more rational 
than those of drying {e.g. by Schaudinn’s fixative) the haemogregarines 
