﻿34 



BtTLLETIN 1369', XT. S. DEPAfiTMElSTT OF AGElCtJLTtTItE 



nil I: 



Fif! 



] i). — Dorsal view of adult male of IJ ijpodermu 

 Uiieatum. Much enlarged. 



them. These hosts were kept securely muzzled throughout the 



season Avhen flies were likely to be about, except for the time that 



they were being fed, 

 when they were placed in 

 specially constructed 

 stanchions which would 

 not allow them to lick 

 any part of themselves. 

 The muzzles used were 

 made of heavy wire, ex- 

 tending well up the nose 

 and covered with closely 

 woven ducking, except 

 for two small holes above 

 the nostrils. 



As will be seen by ref- 

 erence to Table I, dur- 

 ing 1917 three animals 

 (Nos. 164, 169, and 176) 

 were infested by allow- 

 ing flies to oviposit on 

 them. One of these re- 

 ceived the eggs on the 

 heels and thigh, another 

 on the legs, shoulder, and 



neck, and the third on the back. In each of these a considerable num- 

 ber (45, 27, and 10, respectively) of grubs came to the subdermal 



tissue and cut holes 



through the skin of the 



back the following fall 



and winter. Another 



animal (No. 174) was 



given, by way of the 



mouth, 36 newly 



hatched larvae and 82 



eggs which were about 



ready to hatch. Nine 



of these larvae were ad- 

 ministered down the 



throat in a capsule. 



No grubs appeared on 



the back of this animal 



during the fall and 



winter, although it 



was shown that it was 



a favorable host by the 



fact that it had a good 



infestation during the 



previous year. 



In 1918 three ani- ^'''''- ^o- 



mals were used, two of 



these (Nos. 212 and 217) receiving infestations on the heels and one 



(No. 214) by way of the mouth. Both of those having eggs de- 



Doi'sal view of adult female of Hi/poderma 

 ho CIS. Much enlarged 



