TEXAS FEVER. 
171 
- \ 
preceding experiments. These notes give the date of rise of 
fever, its duration and type, whether severe or mild, the condi¬ 
tion of the animal when shipped and the history of the bulls 
after arrival in the south. 
A study of the temperature records and notes shows that, 
as a rule, the inoculation fever begins about the 8th or 9th day 
after the inoculation, sometimes a little earlier and sometimes 
later; and that it usually continues from 7 to 8 days. In some 
cases it may not exceed 4 days, and in others it may be pro¬ 
longed to 15 days. The daily average of the temperature dur¬ 
ing the primary fever period, counting all that reacted distinctly, 
was about 104.5 0 F. 
A remarkable feature observed in this experiment was the 
occurrence in quite a number of animals of a distinct secondary 
fever period, beginning at about the 25th to 30th day after in¬ 
oculation and continuing from 7 to 8 days (in a few cases 4 or 5 
days and in a few from 12 to 16 days). This secondary fever 
as a rule was not so severe as the primary. The graphic rec¬ 
ords, page 26, illustrate this matter of the primary and second¬ 
ary fever periods. In some animals that received but one inoc¬ 
ulation, no appreciable reaction appeared at the usual period of 
primary fever, but came up strongly at the secondary period. 
These bulls were not kept under observation a sufficient length 
of time to determine whether a li periodicity ” occurs in this 
fever, as in malarial (the micro-organism of which appears to 
be nearly related to that of Texas fever). The suggestion arises 
that a tertiary and succeeding recurrences of fever take place, 
each milder than the preceding, until finally immunity is at¬ 
tained. 
The matter of the occurrence of the marked secondary fever 
period has been confirmed in experiment No. 8, carried on dur¬ 
ing the succeeding spring and summer at the Texas Experiment 
Station. In this later experiment five animals were used ; the 
temperature records were taken twice daily, and in a more sys¬ 
tematic manner than was possible in the larger group of the 
above experiment. In addition, regular determinations of the 
