6 BULLETIN 147, U. S. DEPARTMENT OF AGRICULTURE. 
The seed ticks were applied by permitting them to crawl on to 
the cow's hair in various places from the edge of pint fruit jars 
used in hatching them. Sufficient time was allowed after hatching 
to permit the seed ticks to harden and become brown. They had 
been confined in the jars by cotton cloth. This cloth was used 
later to wipe up the ticks and scatter them over the cattle? In the 
first period of the experiment the ticks were mainly placed on the 
backs, bellies, and escutcheons of the cows, but in the second period 
they were placed more generally over the entire body. 
Some of the tick masses became too moist during oviposition and 
incubation in the wet season, and this caused the masses to adhere 
and resulted in the death of the larvae, especially when too many of 
the adult ticks were put together. Previously many egg masses 
had been kept too dry, presumably on account of atmospheric con- 
ditions and the small number of adults placed in a jar. Later on 
better conditions were secured by collecting the ticks in paper bags 
in lots of 200 or 300 and transferring them to the cloth-covered jars 
when they were nearly hatched. 
These methods caused the numbers of seed ticks occurring on the 
cattle to be purely guesswork. Failure resulted in spite of special 
efforts to infest those cattle that presented the fewest adult ticks. 
Such were nearly immune to ticks. 
RESULTS OF EXPERIMENTS. 
The damage done to the infested cows by the ticks seems to have 
arisen from two distinct causes; first, a fever incited in some of the 
cattle at various periods, and, second, loss of blood abstracted by 
the growing tick. 
FEVER CAUSED BY THE TICKS. 
The presence of fever on various dates is shown in Table 2, where 
temperatures of both tick-infested and tick-free cows are shown. 
No attempt was made to take daily temperatures, as the matter of 
taking any temperatures at all was an afterthought rather than part 
of the plan. One set of temperatures was taken at 9 a. m. ; all others 
at 4 p. m. The temperatures of the tick-infested cattle were higher 
than the checks and nearly always above normal. The temperatures 
of the tick-free cattle were also often above normal. This may have 
been due to moist, hot conditions of the atmosphere, since only in 
exceptional cases were the temperatures abnormal on cool days. 
