7 
have had two instances sent me, one in which the maggots sent 
were taken from what in a general way was called the lungs; 
another, last year, when the maggots were sent me as an attack 
apparently affecting the windpipe. 
The exact method and rate of speed of progression of the maggot is 
of a good deal of practical interest, and may easily be seen by 
giving a little attention to the subject. 
In my own observations I found that, whilst I held the maggot, 
the strong black curved mouth-hooks were frequently protruded 
and withdrawn, and were well fitted to act as flat nippers, or 
pincers, to pinch up any soft matter that lay between them, as well 
as to enable the maggot to drag itself onwards, or (at will) to fix 
itself firmly or to loosen hold. The tail segment was (as figured, 
much magnified, p. 5) somewhat rounded, with a slightly swollen 
border, and in the centre of the upper part are the brown plates of 
the spiracles, or breathing-pores, of a shape which might be called 
five-cornered, or three-cornered, with the corners much rounded. 
Beneath these spiracles the caudal or tail extremity of the larva 
was so much enlarged that it projected greatly, forming a central 
lobe bearing a little patch of prickles on its surface ; also it was 
furnished on each side with a fleshy process or projection, appar¬ 
ently very useful in progression. 
The power of rapid movement was remarkable. On placing 
one of the nostril maggots (that is, one of the larvfe of (Estras ovis ) 
on a cloth, it moved onwards at the rate of three and a half inches 
in the first minute, and four and a half inches in the second, and 
when the maggot was placed on the hand the movement could be 
seen to be helped both by head and tail. The black head-hooks 
were almost fixed in the skin of the hand, so firmly that the pressure 
could be felt, and thus served as a power by which the maggot kept 
itself in place whilst the lobe of the tail and the pair of fleshy 
tubercles, or processes, on each side, presumably also the small 
prickles beneath the segments, served as a means to push the soft 
body onwards from the tail end, the maggot thus advancing at a 
very fair pace by alternately pushing and fixing. When placed on 
glass the maggot had a power of movement simply by adhesion of 
its own lower surface. 
The number of maggots found in individual cases of infestation 
varies much. Commonly it does not appear to exceed from two or 
three to six or seven (vide 4 Youatt on the Sheep,’ p. 866, for the 
smaller number, and 4 Animal Parasites of Sheep,’ by Dr. Cooper 
Curtice, p. 31, for the larger number), but very many more are 
