318 KANSAS UNIVERSITY SCIENCE BULLETIN. 



In August, therefore, this part of the study was transferred 

 to Madison river, in the southern part of Montana, where ail 

 stages of the fly were unusually abundant. Here it was ob- 

 served that the fly would bite the exposed parts, and was more 

 active on cool days while the temperature was below 70° F. 



Of special importance was the observation made by four 

 members of the party that the bite of the fly was not always 

 noticeable. For example, the writer sat through an entire 

 evening meal in the tent with the sand fly biting on the face 

 near the base of the nose. He was not aware of its presence 

 there until informed at the close of the meal by his companions 

 regarding the length of the time it had been there. The spot 

 reddened in this case was about the size of a flax seed. 



It seems probable also that it succeeds in attaching itself 

 to the host through its mouth parts, because when once settled 

 down to feeding it sticks to the host and is not readily 

 detached. 



Biting is not uniformly painless, as sometimes the insect 

 could be detected by its first contact. 



Regarding the morphology of the mouth parts, Mr. W. T. 

 Emery, who has been my graduate student assistant in this 

 work, has the paper following, dealing with that phase of the 

 subject. 



A second point to be here recorded is that the monkey, 

 which we used all last year to receive inoculations from the 

 sand fly, and which received its last inoculation on December 

 22, 1912, as recorded in my previous paper, late in November, 

 1913, began to show a marked stomatitis, accompanied by a 

 diarrhoea. She has continued to lose in weight and the color 

 of the face is changing from the normal to a pale ashy gray. 



Summing up the evidence, then, in the work thus far for 

 and against the Sambon theory : 



1. The number of sand flies has been directly proportional 

 to the number of cases of pellagra. 



2. The first appearance of the cases of pellagra is coinci- 

 dent with the principal broods. 



.3. .Just succeeding the time of the principal broods the flies 

 appear to bite more vigorously. 



4. Sand flies which have fed on human blood live several 

 days longer than those which have not been so nourished, thus 

 favoring an incubation period for a parasite, if such there be. 



