202 
HERBERT OSBORN. 
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 thor¬ 
ough 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 j 
seed of common larkspur steeped, and the animal thoroughly | 
washed with the liquid. He says: “ I have known one ap¬ 
plication 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 Delphin¬ 
ium. Washes of carbolic acid soap or of tobacco infusion are 
also effectual, but washes of any kind are of course illy adapt¬ 
ed to use in midwinter, the time when there is frequently 
most necessity for treatment. Mercurial ointment, sulphur, 
or tobacco smoke, kerosene and lard, or kerosene emulsion, 
road dust, ashes, etc., may be resorted to, according to the 1 
circumstances. Infested animals should, if possible, be placed j-j 
apart from the others, and much trouble may be saved by 
this precaution. 
Experiments with fumigation have shown this to be a 
method available 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 ser¬ 
vice as the washes, especially the kerosene emulsion. 
The method may be said in brief to consist of a tight box- 
stall just large enough to admit the largest animal to be 
treated, one end having a close-fitting door to admit the ani¬ 
mal, the opposite end a stanchion in which the animal is fas¬ 
tened, and covering the open part of this end, and made to 
fit tightly around the head just in front of the horns, is a can¬ 
vas sack open at both ends, the inner one nailed to the stall d 
and the outer with a running cord to draw it down to the an¬ 
imal’s head, thus leaving the eyes and nose in open air. An 
opening at the bottom of one side admits fumigating sub- 
