ESTABLISHED WARBLE. 
119 
the growth of the smooth rigid maggot. In my investigations of yet 
earlier conditions I always found a minute channel from the outside of 
the hide to where the embryo maggot lay in the tissues beneath, and 
it appears to me that the enlargement of this passage by the young 
maggot forcing itself, small end foremost, up the ready-made tunnel, 
with its first spring growth, and, gradually enlarging the hole by the 
pressure of its own intensely hard, inflated, and rapidly enlarging 
condition, is the cause of the warble hole. 
Disorganised tissue and ulcerated matter are sometimes dragged 
into the passage by the maggot, and in the opening of the warble we 
sometimes find a slight covering of gummy matter over the tip of the 
maggot, but the great mischief from inflammation, swelling, and dis¬ 
organisation is beneath the hide. 
The above refers to the first state of the passage of the opening 
warble. In a short time the maggot is to he found advanced to its 
oval form, and the passage through the hide to be then covered with a 
coating of some kind of skin, or lining membrane. 
On the 3rd of March Messrs. Hatton further favoured me with a 
piece of heifer hide, less than six inches square, containing twelve or 
more warbles, which had now advanced in growth, so as to show on 
the flesh side of the hide as well-defined lumps, ranging from three- to 
five-eighths of an inch across, and up to as much three-eighths of an 
inch in height of the swelling. 
All that I examined had openings on the upper side of the hide, 
and internally were now coated with a distinct formation of some kind 
of lining membrane, like thickened yellowish skin, continuous with the 
coat of the cell below. As I am not an anatomist, and the nature of 
this formation has been made the subject of minute German investi¬ 
gation and discussion, I merely mention its appearance, and refer to 
the figure, p. 109, drawn from a fully-developed cell last year. 
Within the cells (in the hide above mentioned) the maggots now 
lay, still whitish, and hardly a quarter of their full size, but advanced 
to the compressed oval form, with broad and narrow bands of prickles, 
with kidney-shaped spiracles, and with the mouth end downwards in 
the ulcerated matter in which they were feeding. 
This brings the investigation round to the point at which we 
started,—that of the maggot lying at our disposal in the open cell; 
for, whatever more we may find out, the great point of all that we are 
aiming at is how to destroy the pest; and I fully believe that as a 
beginning, if all who have cattle would have the warbles dressed with 
mercurial ointment , the benefit would be enormous. 
I am greatly indebted to my contributors for the kind courtesy with 
which they have assisted this investigation, and, if they will be kind 
enough to continue their help for a few months longer, we might hope 
