22 
tissues. I found a definite spot where this was going on, 
and, on holding the live maggot in my fingers, I noticed 
a regular expansion and contraction by which the 
tubercles by the mouth and the patches of minute 
Section of Warble, slightly larger than life.* 
prickles round it were kept in perpetual action, and 
apparently as perpetual irritants at this spot. The fact 
of a large part of the cavity being skinned over before 
the maggot leaves it is very obvious on examination; 
and for considerations as to the precise cuticle or epi¬ 
thelium, and the under-coating of newly-formed tissue 
of blood vessels, fat molecules, and other growths of the 
nature of true skin which form over the healing surfaces, 
I refer you to the anatomical investigations of the subject 
given by Friedrich Brauer. 
These points are of interest as showing why, though 
when the maggot is gone, the walls of the cell may draw 
together, there is good reason not to expect the already 
skinned over surfaces will form solid union. 
The specimen of leather which I hold up before you 
has about twenty-four holes caused by the Warble maggot 
in a length of 12 in. by 8 in.; this other piece has about 
seventeen holes in nearly the same measurement; and, 
if you multiply this by the extent of skin often attacked 
on the hack and loins of the cattle, and by the large 
percentage of the cattle that are thus attacked, it will 
be obvious that the evil calls for serious attention. 
* The above figure was taken from a warble that had been soaked 
for about a fortnight in brine, and shows the growth of firm skin 
on each side of the section of the upper portion of the cavity, and « 
also the large size of the sac formed in the lowest tissue of the 
hide, as seen when the hide is removed from the infested animal. ^ 
