EFFECT OF CATTLE TICK ON MILK PRODUCTION. 3 
period. The body weights were taken for 10 consecutive days at 
the beginning of the work; thence once every 10 days until the last 
period, when they were taken for 10 consecutive days as at the 
beginning of the work. The weights were taken at about the same 
hour and under the same conditions each time, so that the extent 
of fill, both as regards feed and water, would be similar. The treat- 
ment of the two groups in all respects other than ticks was as nearly 
alike as possible. 
FEEDING. 
The tick-free group of cattle were fed as much alfalfa hay as they 
would eat readily, and enough corn chop, wheat bran, and cottonseed 
meal, mixed in the proportions 4 : 2 : 1, to maintain the body weights. 
The aim was to give the infested group the same kind and amount 
of feed, but toward the close of the experimental period these cows 
failed to consume as much hay as the tick-free cows. In order to 
make the digestible nutrients consumed practically equal for each 
group, the grain ration of the infested cows was raised 1 pound for 
each 2J pounds of hay refused. Both groups of cows had access 
to salt and water in unlimited quantities. 
THE TICKS. 
The seed ticks used to obtain the various degrees of infestation in 
the cattle were the progeny of mature ticks obtained from several 
sources. The supply of ticks was secured through the cooperation 
of Dr. Charles F. Dawson, of the Florida State Board of Health, as 
the local supply was insufficient. Dr. Dawson's first material was 
collected from Tallahassee, Kissimee, Dade City, and other places in 
Florida. A few small lots were received subsequently. The earlier 
adult ticks were collected between April 13 and April 28. The seed 
ticks or larvae from eggs laid by these emerged between May 22 and 
June 2, following. On June 12 and 14 two other consignments were 
received. The resulting broods seemed sufficient to insure thorough 
infestation of the cattle during the first weeks of the experiment. 
A second source of seed ticks was the Anthony Farm cattle 
not under test. This supply, together with that already mentioned, 
was sufficient to last until the middle of July by applying them but 
once a week. These two sources of supply proved to be insufficient, 
and a third lot was obtained from the Zoological Division of the Bureau 
of Animal Industry. These were mainly a portion of the original col- 
lection by Dr. Dawson, which had been sent by him to Washington and 
intended for another purpose. One flask of specimens labeled as 
originating in Texas accompanied these. This Washington consign- 
ment was applied during July. As fast as the ticks matured on the 
