Insects and Disease 



land and twenty-five hundred feet higher, where 

 they are safe, for no Stegomyia have ever been 

 found there. 



They claim there that the yellow fever mosquito 

 does not bite during the daytime after she has 

 laid her eggs, and that she will not lay her eggs un- 

 til about three days after she has fed on blood, 

 therefore a Stegomyia that bites during the day 

 will not carry the yellow fever because she is too 

 young. This seems to explain why the fever can- 

 not be contracted by being bitten by a mosquito 

 in the daytime. Certain other experiments, how- 

 ever, have given different results so that as far as 

 we know it is not safe to be bitten at any time by 

 such a mosquito in a region where the disease is 

 endemic or where it is epidemic. 



In the main the work of the French Yellow 

 Fever Commission working in Rio de Janiero has 

 confirmed the findings of the American Com- 

 mission. One interesting special thing that the 

 French Commission seems to have established is 

 that the female may transmit the infecting power 

 to her offspring, so that it would be possible for 

 a mosquito that had never bitten a yellow fever 

 patient to be capable of infecting a non-immune 

 person. While all this is very probable in the light 

 of what we know of the disease and the way in 



