Investigations into the Nature, Causation, and Prevention of Texas or Southern Cattle Fever Page: 92
301 p. : ill. (some col.) ; 24 cm.View a full description of this book.
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TEXAS OR SOUTHERN CATTLE FEVER.
animal. What becomes of the ticks not yet matured, which are at.
tached to the skin of natives when the latter succumb to Texas fever,
we can not state definitely. It is certain that they do not at once leave
the dead body, for in the case of cattle which die early in the night the
ticks are still found attached next morning. In the case of a calf kept
in a large refrigerator several were found attached forty-eight hours
after death. If ticks are removed by the hand from the dead body it
will be found that the males as well as those females which have passed
through the second moult move about with some show of activity, while
those individuals which have not yet cast off the moulted skin are mo-
tionless. Taking these facts into consideration, we must regard the
movement of ticks from one animal to another as an unnatural process
which, so far as we know, may take place, but which from general ob-
servations does not appear to be of much importance. Still, it is never-
theless desirable that experiments be made to determine positively
whether ticks may be transplanted after the last moult, and whether at
this advanced stage in their life history they are still capable of pro-
ducing Texas fever.
Paquin states (9, p. 45) that full grown ticks contain the 6bacteria"
of Texas fever. In order to see whether ticks contain bacteria, and
what kind, the following inoculation experiments were made:
(1) July 7, 1890.-A large North Carolina tick was taken and its back scorched
through with a red hot platinum spatula, thus exposing the body cavity. A loop of
the black tarry contents transferred to peptone bouillon. A coccus, arranged in the
form of tetrads, produces a faint cloudiness and a deposit in the inoculated tube.
(2) A second tick from the same source treated in the same way. The culture con-
tains a coccus of the same form.
(3) July 10, 1890.-From a large tick from Texas cattle a peptone bouillon tube in-
oculated. Remains sterile.
(4) Another large Texas tick used. The resulting peptone bouillon culture coin-
tains a flocculent growth of large bacilli in chains.
(5) July 18,1890.-An agar tube inoculated from a large tick, as before. Remains
permanently sterile.
(6) Another agar tube inoculated from another tick. A considerable number of
small colonies develop, having an opaque center and translucent periphery. They
are made up of short bacilli.
(7) A peptone bouillon tube inoculated from a large tick becomes clouded with
large motile spore-bearing bacilli.
These experiments show that the tick may harbor a variety of bac-
teria or none at all.
FIELD EXPERIMENTS TO DETERMINE THE PRECISE RELATION BE-
TWEEN THE CATTLE TICK AND TEXAS FEVER.
These experiments were begun in the summer of 1889 and have been
continued up to the present. They have been carried on in thre-dif-
ferent directions:
(1) Ticks were carefully picked from Southern animals, so that none92
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Smith, Theobold & Kilborne, Fred Lucius. Investigations into the Nature, Causation, and Prevention of Texas or Southern Cattle Fever, book, 1893; Washington D.C.. (https://texashistory.unt.edu/ark:/67531/metapth143538/m1/92/: accessed April 23, 2024), University of North Texas Libraries, The Portal to Texas History, https://texashistory.unt.edu; crediting University of Texas Health Science Center Libraries.