Appendix A. 69 



(Referred to on page 02 as reproduced circulars of) 



DEPARTMENT OF HEALTH, 



CITY OF NEW YORK. 



55th Street and Sixth Avenue. 



CIRCULAE IN EELATION TO TEE LIFE HISTORY AND THE 

 EXTERMINATION OF MOSQUITOES, AND THE PRE- 

 VENTION OF MALARIA. 



The Department of Health has become convinced, from many successful 

 efforts elsewhere, that the mosquito evil in and around New York, bringing 

 with it great discomfort and annoyance, a needless depreciation of prop- 

 erty values, and THE DANGER OF MALARIA, is preventable. Preven- 

 tion, moreover, in many instances is comparatively simple and inexpensive, 

 requiring on the part of householders and property owners only a rea- 

 sonable willingness to cooperate with the Department. This circular is 

 issued in order that the general public may be informed as to the steps which 

 areliecessary to exterminate mosquitoes altogether, or render their numbers 

 insignificant. 



THE CAUSATION OF MALARIAL FEVER 



Recent investigations have shown that malarial fever (also called "ague," 

 "chills," "chills and fever," "dumb ague") is a disease which requires for 

 its transmission the active services of a definite kind of mosquito, i. e.. Ano- 

 pheles. 



The organism causing malarial fever (the Plasmodium malaria) is a true 

 parasite, and so far as we know finds the conditions necessary for its exist- 

 ence only in the human bipod, and this species of mosquito. The insect be- 

 ccmcs infected by sucking the blood from an infected human being. The 

 malarial organism having thus entered the stomach of the mosquito, passes 

 through certain changes of its existence in the body of the insect, and at the 

 end of about 8 days reaches the poison gland. After this time, if the mos- 

 quito bites another human being, the malarial organism is introduced into 

 the circulation of the latter, and malarial fever follows. 



So far as wo knew certain localities are malarious only because the;/ fur- 

 nish favorable conditions for breeding the Anopheles mosquito. Malarial 

 fever, however, would not occur in any malarious district unless some in- 

 fected human being were in it, or came into it, and infected the mosquitoes, 

 which in turn, infected other human beings. 



