16 
PROPHYLAXIS OF MALARIA. 
absolutely essential to one who hopes to achieve success in prophy¬ 
laxis. This does not mean that one must be a professional protozo¬ 
ologist or entomologist, for a good working knowledge of these sub¬ 
jects may be obtained from the careful study of the blood from a 
few cases of malaria and from the investigation of the structure and 
habits of a few species of mosquitoes. One should be able to recog¬ 
nize the various forms of the malaria plasmodia occurring in the 
blood of man and also be able to differentiate mosquitoes belonging to 
the Anophelina ? from other mosquitoes, and, fortunately, this knowl¬ 
edge may be easily acquired by anyone who has access to the neces¬ 
sary material. 
As the first step in any successful attempt at the prophylaxis of 
malaria is the diagnosis of the presence of infection either in man or 
the mosquito, it is necessary to consider as briefly as is consistent 
with the importance of the subject the methods of demonstrating the 
parasites and their morphology and life cycle. The discovery of 
“ carriers v of the infection, so important from a prophylactic stand¬ 
point, and the proper treatment of all malarial disease, depends upon 
the recognition of the plasmodia in the blood of man, while no mala¬ 
ria survey can be called complete which does not include the demon¬ 
stration of the plasmodia within the mosquitoes of the locality in¬ 
vestigated. In the following sections dealing with the plasmodia and 
the mosquitoes transmitting them I have endeavored to give the facts 
that are most essential to one working along the line of prophylaxis; 
and while it has been necessary to describe the morphology of the 
plasmodia I have limited myself as much as possible in the descrip¬ 
tion, placing special emphasis upon the forms of the plasmodia that 
infect the mosquito and that may also be demonstrated in the blood 
of man, i. e., the gametes. No attempt has been made to describe in 
detail the anatomy of mosquitoes, but special attention has been paid 
to the broad points differentiating the Anophelinai from other mos¬ 
quitoes and to the habits of certain species transmitting the malarial 
fevers. The methods of demonstrating the plasmodia are those that 
I have found most useful and can be easily applied by anyone hav¬ 
ing a knowledge of the microscope and of microscopical technique. 
Fort Leavenworth, Kansas, 
July, 191 
