126 MALARIA 



immediately contiguous to the river, the region is 

 not naturally suited to a prevalence of malaria, and 

 that the presence of malaria is due almost entirely to 

 artificially produced conditions. 



Prevalence of Malaria. — - I was unable to obtain any 

 information in the field as to the exact type or types of 

 the malaria parasite present in this region, as the mak- 

 ing of blood smears was not possible, owing to the fact 

 that every person known to me having malaria had been 

 taking quinine recently, which would make a determina- 

 tion by blood examination unreliable. From what I can 

 find out, the infection is of a very mild form, incapacitat- 

 ing a person for a few days on arrival, and not subject 

 to frequent relapse. I will endeavor to find out as 

 much as possible from the physicians in Red Bluff who 

 attend cases in the vicinity of Los Molinos, and report 

 the information in an appendix to this report at a later 

 date. There is no doubt, however, that it is a true 

 malaria, and can be controlled by the usual prophylaxis. 



Presence of Mosquitoes. — The month of September, 

 especially the latter part of it, is well along toward the 

 latter part of the mosquito-breeding season, and it 

 was not expected that they would be particularly 

 noticeable. They were sufficiently in evidence in the 

 evening during my visit to show that they were fairly 

 numerous. Both types, Anopheline and Culicine, were 

 seen in larval as well as adult form. The Anopheline 

 mosquitoes were apparently mostly Anopheles maculi- 

 pennis, this being the only one identified, but others 



