The Irish Naliiralist. 
October, 
be taken to support the view that the maggot enters the 
host -animal by the mouth, though the fact that the 
experiment was carried through on two animals only makes 
any conclusion on the subject very doubtful. In 1908 the 
same course was pursued, and it was found that in the 
spring of 1909 the six beasts which had been muzzled 
showed, on an average, 9* 16 warbles each, and the thirty 
"controls" 12 each. Here, therefore, with a fair number 
of experimental calves, the result resembled that of 1906-7, 
and once again supported the theory of entrance by the 
maggot through the skin. 
During the summer of 1909 the experiment was repeated 
with the additional precaution of a strong wire cage sur- 
rounding each leathern muzzle, so that the leather could not 
touch any part of the animal's body, and the bare possibility 
of eggs or maggots being sucked in through the breathing - 
holes was obviated. Five calves were thus muzzled, and 
fifteen were left untreated ; in the spring of 19 10 the former 
had an average of 2 warbles per head, the latter of 6*3, 
and it was found that all the maggots from the animals that 
had been muzzled were extracted in April, none being 
visible at the second count of warbles in May. In the 
summer of 191 1 the same arrangement was tried again, ten 
calves being muzzled and seventeen left to graze normally, 
the average for the former lot was 8 4, for the latter, 12*9, 
and again it was found that all the maggots in the beasts that 
had been muzzled "ripened" early; none were extracted 
at the second count. These results suggested that muzzling 
might give at least partial protection. 
In all the summers thus far mentioned the muzzled calves 
and their "control" companions were allowed to wander 
at will all over a certain field. It was noticed that the 
muzzled calves— probably on account of not being able to 
graze' — were often assembled at the edge of th6 pasture, 
where they were sheltered by hedges or trees, while the 
" control " animals were wandering in the middle of the field ; 
as the warble -flies are on the wing only in bright sun- 
shine, the latter were, in such conditions, clearly more open 
to attack than the muzzled beasts. When the experiment 
