REPORT OF THE COMMITTEE ON DISEASE. 
781 
examined and their temperatures taken daily. Leaving out 
of account certain failures which occurred in the first year of 
these experiments, and due, no doubt,'to the lateness of the 
season, the general result was this: From four to seven weeks 
after their introduction the first ticks were observed on the 
cattle. These were all of small size and could be seen only 
by careful examination ; about the same time there was ob- 
• served a rise of temperature, with more or less signs of ill 
health and loss of appetite, which in most cases continued for 
several weeks before a slow recovery took place. In a few 
cases the disease was not of much severity, but generally the 
attack was severe, although not fatal. These tests were made 
with young cattle of from one to two years old. Post mor¬ 
tem examinations were made in a number of the cases which 
were killed during the height of the fever, and later, during 
convalescence, and the diagnosis of Texas fever confirmed 
both by the gross anatomical appearances and by a microscop¬ 
ical examination. The ticks attained their full growth on 
these cattle about two or three weeks from the time of their 
first appearace. These, of course, were not the original ticks 
thrown into the pens, but the next generation hatched from 
their ova deposited on the soil. This experiment illustrates 
the way in which pastures become infected by southern tick¬ 
bearing cattle. 
“ In other experiments the ova deposited by large cattle 
ticks sent to me by Dr. Dalrymple, late of the Louisiana 
Agricultural Experiment Station, were allowed to hatch out 
in glass dishes in the laboratory and the young were then 
sprinkled over the bodies of susceptible cattle. The result 
was the same, except that the first symptoms of the fever ap¬ 
peared in from ten to fourteen days. These ticks in this last 
test attained their full growth in about four weeks. When 
full grown the females were picked off and placed in the 
laboratory in glass dishes where they immediately commenced 
their egg deposition, and in a few weeks later another gener¬ 
ation of young ticks was obtained. In the first week of Octo¬ 
ber the ticks from this second generation were placed on two 
cattle in a fresh pen, and in two weeks both of these cattle 
