34 BULLETIN 1369, U. S. DEPARTMENT OF AGRICULTURE 
them. These hosts were kept securely muzzled throughout the 
season when flies were likely to be about, except for the time that 
they were being fed, 
when they were placed in 
specially constructed 
stanchions which wouid 
not allow them to lick 
any part of themselves. 
Thé 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 alliow- 
ing flies to oviposit on 
them. One of these re- 
ceived the eggs on the 
Bic: 19. Dacia ew of call pate (oF atatme helen le ee 
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, 386 newly 
hatched larve and 82 
eggs which were about 
ready to hatch. Nine 
of these larvee 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. eves 
In 1918 three ani- F!%: a Sig aerate Mach sheet of Hypoderma 
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- 
