Proteosoma to Birds ~by the Mosquito. 447 



8. The coccidia (pigmented bodies) found on the second day 

 measured 6 7 ft, some of them a little more. They were oval 

 bodies containing scattered granules of black pigment, and had a 

 sharp, clear outline. 



I incised the stomach of infected mosquitoes and by repeated wash- 

 ing and compression with a cover glass was able not only to wash out 

 the contents, but even to express the loosely attached epithelium, so 

 as to leave the stomach a transparent clear bag. The majority of 

 coccidia remained fixed to the outer wall, though in one of the 

 mosquitoes I observed a few coccidia escape with the epthelium. On 

 subsequent attempts to detach the coccidia by this process I failed to 

 do so, though some coccidia would be ruptured. 



The next morning the smallest coccidia measured 10 ft some were 

 12 ft. On the sixth day they were met with up to 30 ft; by this time 

 the pigment had absolutely as well as relatively diminished. 



In another three days some of them reached 60 ft ; and in the last 

 of the series examined (tenth day), there were coccidia measuring 

 70ft. 



The coccidia could now be seen to project from the outer wall of 

 the stomach; very few contained pigment, and that only in small 

 amount. 



Some of the coccidia were clear, and others had a granular appear- 

 ance j but in none were either black spores or germinal threads to be 

 seen. 



9. For the observation of the further development of the coccidium 

 the early deaths of the mosquitoes, owing to the inclemency of the 

 weather, rendered this series useless. 



One of the insects infected on the night of January 5, and another 

 infected on January 7, did reach this more advanced stage ; and in 

 the last of those fed on January 5, and which died on January 22, 

 ruptured cysts, as well as numerous cysts containing mature germinal 

 threads were found by me in the stomach wall, these threads were also 

 found in the body fluids and in cells in the salivary glands. In one 

 of the mosquitoes infected on January 5, which died on January 19, 

 the coccidia had an appearance of striation. 



In consequence of the effects of the unfavourable climatic conditions 

 on the experimental insects, my observations on the development of 

 the proteosomal coccidium were mainly made on mosquitoes infected 

 November 30 and subsequent dates before my arrival, and on some 

 infected on December 22. 



On adding salt solution (15 grs. to the ounce) to an ordinary slide 

 containing an infected mosquito stomach, and pressing on the cover 

 glass, a projecting coccidium was ruptured; the contents poured out 

 into the fluid, leaving the cyst wall still attached to the stomach. 



The contents were seen to consist of a mass of shrivelled threads. 



