HEMIPTERA. 175 
by pushing off the cap-like portion or by simply pushing through this 
portion, which appears to be thinner than the rest and may be simply 
membranous, is not, so far as we know, determined. No marked 
changes, except in size and the development of the chitinous patches, 
occur from hatching to maturity. 
This is one of the most difficult parasites to destroy, and once settled 
upon an animal should receive prompt and thorough treatment. The 
main reliance of veterinarians seems to be stavesacre, and this can 
doubtless be depended upon to accomplish the desired end. Mr. Tenney 
recommends the seed of common larkspur steeped, and the animal 
thoroughly washed with the liquid. He says: “I have known one 
application to destroy every insect and egg; two will suffice if done 
thoroughly.” Of course this and the stavesacre are nearly identical, 
both plants belonging to the genus Delphinium. Washes of carbolic- 
acid soap or of tobacco infusion are also effectual, but washes of any 
kind are of course illy adapted to use in midwinter, the time when there 
is frequently most necessity for treatment. Mercurial ointment, sul- 
phur, or tobacco smoke, kerosene and lard, or kerosene emulsion, road 
dust, ashes, etc., may be resorted to, according to the circumstances. 
Infested animals should, if possible, be placed apart from the others, 
and much trouble may be saved by this precaution. 
Experiments with fumigation have shown this to be a method avyail- 
able when other plans are undesirable, though from the equipment 
necessary, and the fact that it requires some time in application, it may 
not prove of as general service as the washes. 
The method may be said in brief to consist of a tight box stall just 
large enough to admit the largest animals to be treated, one end having 
a close-fitting door to admit the animal, the opposite end a stanchion 
in which the animal is fastened, and covering the open part of this end, 
and made to fit tightly around the head just in front of the horns, is 
a canvas sack open at both ends, the inner one nailed to the stall and 
the outer with a running cord to draw it down to the animal’s head, thus 
leaving the eyes and nose in open air. An opening at the bottom of 
one side admits the fumigating substance, sulphur or tobacco, the latter 
apparently the most effective. In burning this we used a wire screen 
to spread the tebacco, placing this over a tin trough containing a small 
quantity of alcohol. It should be burned, however, with coals or by 
using a small quantity of kerosene. The time of exposure necessary 
will vary some with the strength of fumes, but 1 to 2 ounces of tobacco 
and exposure of twenty to thirty minutes was found effective. Pyre. 
thrum might be better even than tobacco. 
This species has been said to occur also on horses; but if this is the 
case it must be in rare instances, and there need be little apprehension 
of horses becoming infested with it by transmission from cattle with 
which they may be associated. 
