334 
J. W. CONN AW AY. 
cattle, dated August 29, 1899, says that all of the above cattle 
have done well and he thinks all the heifers are safe in calf. 
No deaths. 
SUMMARY AND CONCLUSIONS. 
The Inoculation Fever and Immunity .—The reports on the 
Tod cattle, page 24, and the “ College Station ” lot, page 43, 
present the important features of the inoculation fever, such as 
incubation period, duration and severity of the primary and 
secondary fevers. Attention is called in the graphic record to 
the sudden fall of the primary fever *, this occurs in many 
cases, and appears to be the critical period. At this time col¬ 
lapse and death may occur in severe cases. 
The variation in the percentage of corpuscles during the 
fever, in comparison with the variation of temperature, is 
shown in College Station experiment, see chart, page 65. It 
will be noted that the diminution in corpuscles corresponds 
closely to the rise of temperature, but continues for a time after 
the temperature has fallen ; and that during the interval be¬ 
tween the primary and secondary fever periods, the percentage 
rises, but falls again on the occurrence of the secondary fever. 
The table, page 47, gives the hsematokrit readings for each 
animal, and the average for the group. 
It must always be kept in mind that the inoculation fever 
is o-enuine Texas fever, and that in some cases it will take an 
acute course and cause death in the inoculated animal. A few 
words in regard to the pathology of Texas fever and how im¬ 
munity against it is acquired and maintained, will aid in the 
more intelligent handling of inoculated cattle, both during the 
course of the inoculation fever and during exposure to the in¬ 
fection at the South. 
When a susceptible animal is infested with ticks or is inoc¬ 
ulated with infected blood, the micro-parasites thus introduced 
attack the blood corpuscles and destroy them in large numbers. 
This is the essential pathological change in this disease. As a 
result, the oxygen carrying function of the blood is greatly im- 
