I9I4- Carpenter & }^v,-^\'t'T.—IIislory of Warhlc Flics. ^19 
the more abundant ; and it is well known that the latter 
species appears later in the summer than the former. In 
the first week of June Mr. Duncan told us that eggs of //. 
lineatum were plentiful on cows at Athenry, on the hairs of 
the thighs not far below the root of the tail, and that a few 
days after the eggs had been laid Messrs. Smith and Lang 
observed a soreness in the neighbouring region of the skin 
with a discharge of matter. One of us (G. H. C.) accordingly 
went to Athenry accompanied by Mr. T. K. Reddin, 
M.R.C.V.S., who is associated with us in this enquiry. The 
region of the body where these eggs were laid was very 
convenient for examination, and the milch cows, standing 
quietly in the byre, were much better subjects for observa- 
tion than restless calves in the field. We found that the 
cow's skin near the newly-hatched eggs was perforated by 
minute holes from which flowed a watery discharge which 
hardened on the surface to a scaly deposit, and that after 
a day or two the region affected became covered with small 
pimples ; these disappeared a few days later. On squeezing 
the skin of the earliest " case " that could be obtained, some 
clear, watery fluid exuded, and a smear of this examined 
microscopically was found to contain a newly-hatched 
maggot of Hypoderma lineatum. 
This satisfactory observation incited to further work at 
the problem later in the summer with H. hovis at Ballyhaise, 
where one of us (T. R. H.) has been in charge of the experi- 
ments during the past two seasons. In July twenty-four mag- 
gots were hatched in the incubator, and some of these were 
used for observations as to behaviour when placed on a calf's 
body. Glaser, in 1913, had tried to carry out observations of 
this kind, by placing maggots on a shaved portion of a calf's 
skin ; he found that they made no effort to bore through. 
Instead of being shaved, a small patch on the shoulder of 
one of the Ballyhaise calves was chpped, so as to have the 
conditions as normal as possible, and newly -hatched maggots 
of H. hovis were placed on it. Immediately they started 
crawhng down the clipped hairs to the skin, and, as soon as 
they reached the surface, they began to burrow. On 
account of their small size it is hard to discern them, but by 
