INSECTS AND DISEASE. 645 



as also its greater frequency in Siberia and Lapland, where insects of 

 the mosquito tribe are the great pest of the traveler. In Lapland the 

 popular belief was long ago universal that the disease was caused by a 

 peculiar insect, which suddenly descended from the air, and as suddenly 

 disappeared. In the London " Times" (1860) it is reported that four 

 hundred persons lost their lives in the south of Russia and in the 

 province of Kiev from the sting of a " venomous fly " imported from 

 Asia, the same fly having made its appearance there on another occa- 

 sion, sixty or seventy years before. Virchow, who has made malig- 

 nant pustule a special study, says : " Most probably, insects with pierc- 

 ing probosces effect the inoculation, such as gadflies (Bremse) ; but 

 flies which make no wound may also implant the poison on the skin 

 by their soiled wings and feet." The bites of these same flies may be 

 generally harmless ; they have no venomous power of their own, but 

 only convey poison from sources of infection to man and animals. 



Furthermore, when it is remembered that disease-producing bacte- 

 ric germs are so minute that a million may rest on the head of a pin, 

 and that the smallest puncture of the finest needle-point (as in Pas- 

 teur's experiments with chicken-cholera), when charged with an atom 

 of infecting matter, may be sufficient to infect the body with the sep- 

 tic matter, it scarcely seems possible to ignore any longer the punc- 

 tures of mosquitoes and other proboscidian insects as possible sources 

 of both infection and contagion. With our present knowledge of the 

 "germ theory" one would hardly dare, even once, to plunge an inocu- 

 lating needle into the blood of a yellow-fever or typhus-fever patient, 

 whether living and comatose or recently dead, and then withdraw it 

 and plunge it into his own blood or the blood of other persons, yet this 

 is exactly what the mosquito is doing in nearly every yellow-fever epi- 

 demic, and what, perhaps, the flea is doing in the filthy jails and ships 

 infested with t3^phus. In the yellow-fever instance, it is to be noted, 

 also, that the spread of the disease ceases with frost ; so also do the 

 peregrinations of the mosquito. 



In this paper, however, my chief design is to present what facts I 

 may be able in support of the mosquital origin of malarial disease 

 in fact, of ague. And, while the data to be presented can not be held 

 to prove the theory, they may go so far as to initiate and encour- 

 age experiments and observations by which the truth or fallacy of 

 the views held may be demonstrated, which, either way, will be a 

 step in the line of progress. It is scarcely necessary to premise that 

 other nay, all insects that infest and wound the human body may 

 share in the guilt that will here be charged, in particular, to the ctdex; 

 and so, of course, other diseases than ague, yellow fever, etc., may 

 possibly have a similar history. Be it noted en passant that, so far 

 back as 1848, Dr. Josiah Nott, of Mobile, Alabama, published a 

 lengthy essay on yellow fever, in which he maintained the insect origin 

 of that disease, and also suggested the "mosquito of the lowlands" 



