No. 8.—ANATOMY OF BOOPHILTJS ANNTJ- 
LATUS SAY. 
BY S. R. WILLIAMS. 
Introduction. 
For many years the cattle disease, Texas fever or redwater, has 
been under more or less careful observation in the southern part of 
the United States. Since the tick, Boophilus annulatus , has been 
demonstrated to be the source of infection for this disease it has 
received its share of attention. Its habits, life history, and external 
anatomy have been described at length. No description of its inter¬ 
nal anatomy, however, has been published. 
In the last few years the discovery of the full history of malaria 
renders it probable that the Sporozoa which cause many of our dis¬ 
eases, Texas fever among others, will be found in altered form in a 
second host from which the first species must be re-infected. We 
know that the tick is the alternate host for this parasite, and any con¬ 
tribution to a clear knowledge of its anatomy must be of use in the 
future tracing out of the portion of the life cycle of the fever-produc¬ 
ing organism which is passed in or on the Texas fever tick. 
There is much literature on the group of ticks as a whole, but the 
different families vary so exceedingly in type that a description of 
one species will not hold for a closely related form. For example, 
the most considerable paper on a near relative of Boophilus, that of 
Pagenstecher (’61) on Ixodes ricinus , the castor bean tick, shows 
that Ixodes differs greatly from Boopliilus annulatus in almost 
every organ. 
I wish to thank Prof. Mark Francis, of the Texas agricultural 
and mechanical college, for the material studied. 
Material and Methods. 
I received from Dr. Francis the gravid females, immature females, 
and males. Some of the gravid females laid eggs in the box in 
which they had been sent; others oviposited in the laboratory. 
The animals were killed in hot water, Perenyi’s, corrosive-acetic, 
