108 



Table 1. — Summary of inoculations of nonimmunes by hereditarily infected (?) mosq 

 toes — subjects kept under observation at least seven days after each inoculation. 



[The mosquitoes are designated by numbers from 1 to 14; nonimmunes by capital letters.] 



"Subject passed from observation after 6 days. 

 6 Subject passed from observation after 5 days. 



A factor in the problem which is of prime importance and whic 

 must always be reckoned with in estimating the value of negativ 

 results is the susceptibility to the disease of the subject used for ti 

 inoculations. We were careful to select only those who we were sai 

 isfied never had had the disease. 



Another factor which must be considered is temperature. No mer 

 tion is made in the paper of Marchoux and Simond at what tempers 

 ture their mosquitoes were kept. Our mosquitoes were kept unde 

 artificial conditions at a temperature of between 80° and 90° F (Se 

 p. 109.) * v 



Many other factors which we shall not discuss undoubtedly ente 

 into and affect this problem. 



DETAILS 01 EXPEKIMENTS. 



In our study we used three sets of Stegomyia fasciata, comprising 

 fourteen insects, the progeny of three mothers that had fed on yellow 

 fever. The history of these mosquitoes is as follows: 



Set 1, Groups land II, mosquitoes Ms. 1, 3, 3, and J,.. 



Mother mosquito.— The mother mosquito of this set was one of i 



number raised from the larval stage in our laboratory, and, withou 



any prior feeding, was made to sting, on October 3, at 5.20 p. m. t 



patient (Melancon) with a severe case of yellow fever, 14£ hours aft'e' 



. the initial chill; about 42 hours later this mosquito was again mad. 



