On the 3rd of March, Messrs. Hatton sent Miss Ormerod 
a piece of heifer hide less than 6 inches square, containing 
twelve or more warbles, which showed on flesh side of hide as 
well-defined lumps ranging from § to f- of an inch across, and 
f of an inch in height of swelling. All had openings in upper 
side of hide, and internally were coated with a distinct forma¬ 
tion of some sort of lining membrane, like thickened yellowish 
skin, continuous with the coat of cell below. Within the cells, in 
same hide, the maggots lay, still whitish, hardly a quarter of full 
size, but advanced to the compressed oval form, with broad and 
narrow bands of prickles, and with kidney-shaped spiracles. 
The spiracles are placed at the extremity of the body 
instead of on the sides as usual, in order, as it would seem, to 
avoid the necessity of having a large orifice in the swelling, 
which would interfere with the comfort of its temporary 
occupant. The orifice is about -§ inch in diameter at the top, 
gradually increasing until it has passed through the firm 
parts, when it bends in its course, and forms an irregular bag 
about 1 inch long in the sub-cutaneous tissues. In this bag 
or sac the maggot lies slantwise, with its tail in the orifice and 
its mouth-end downwards. 
The duration of special habits of life in the maggot may 
be divided into three periods :—1st, The youngest state, when 
its chief work appears to be to make its way through the hide 
downward ; 2nd, When it starts into the active state which 
precedes its first obvious appearance in the opening warble, 
and in which its most important work is forcing its way up 
again, tail foremost; 3rd, In which, having formed the open¬ 
ing, it lies within, feeding, mouth end downwards, in the filthy 
discharge its own presence causes, until it is ready to leave 
the hide. In forming the perforation, 
the tip of the tail of the maggot, which 
is ended in this stage of its life by two 
somewhat club-shaped spiracles, which 
when highly magnified appear like short 
bent cylinders, as in figure 10. These 
are composed of horny or chitinous 
materials, and each of them is placed at 
the extremity of a large trachea or Pig . ,o.-Spirack Tube(o„eof 
breathing tube, which pair of tracheae are the pair )> much ma s mfied - 
