AUTUMN NUMBER 19 
about the same time Dr. Finley of Havana, Cuba, presented his 
facts in regard to mosquito transmission of yellow fever. 
To return to the topic of discussion for this evening, we find 
as intermediate hosts for the malaria plasmodum, three species 
of Anepholes mosquitoes, namely: A. crucians, purely south- 
ern species; A. quadrimaculatus, a species of general distribu- 
tion; and the third species causing the transmission is A. punc- 
tipennis, which is also of general distribution. These mosqui- 
toes are the agents of transmission for a protozoan blood para- 
site which causes a breaking down of the red blood corpuscles, 
and produces a condition commonly termed “chills and fever,” 
or malaria. In favorable conditions these fever attacks occur 
every 48 hours. 
Three principal types of the disease are known. They are: 
1, the benign-tertian, caused by Plasmodium vivax, which com- 
pletes its cycle of development every 48 hours, producing the 
feverish condition. This type is wide spread and common; 2, 
the quartan fever caused by Plasmodium malaria, having a 
cycle of 72 hours and is more prevalent in temperate and 
tropical regions, but appears rarely everywhere; 3, sub-tertian 
or pernicious fever caused by Plasmodium falciparum. This is 
an irregular type of fever and the life cycle of the parasite 
takes place in the internal organs, principally the spleen, in- 
‘stead of in the peripheral circulation. 
Being accustomed, as we are, to malaria in this country, 
little importance do we place upon it, yet if we should look on 
the mortality side of the question, the facts no doubt appear 
astounding. In Italy it causes an average annual mortality of 
15,000 out of each 2,000,000 cases. In India it claims annually 
1,136,000 persons. In 1911 in Alabama 70,000 cases of ma- 
laria were known and of this number 770 cases were fatal. 
From my personal observation in South America, and also 
in the Mississippi Delta region, I should say the figures for 
Alabama are very conservative. 
Having briefly passed over a few of the important facts let 
us turn back to the life cycle of the Plasmodium vivax and see 
the importance of the mosquito in its development. 
In the adult stage Plasmodium vivax is found living as an 
amoeboid, intracelluiar parasite in the red blood corpuscles of 
man. In the life cycle two well defined stages are noted; Shiz- 
ogony (fision), and Sporogony (or spore formation). 
(Continued on page 22) 
