FORMATION OF MEMBRANE. 
13 
Mr. Macadam gave me details of appearance of the maggots reminding 
“him of cattle-bots ” ; these he destroyed in boil or warble-like 
swellings, simply as we often do here, by excluding air, and drew up 
the description of the pain as being that of “an ordinary sore plus the 
intense itching.” 
Independently of effects on the constitution of inflammation, and 
ulceration (when cattle-attack is on a large scale), it certainly cannot be 
desirable, if their sensations are like those described, that even on a 
small scale they should be troubled by the pain of sores plus the intense 
itching, and also plus (what our warble-maggots have quite structural 
appliances to cause) pain, at times “ quite sharp, as if the maggot was 
screwing itself round in its hole.” 
Formation of membrane or false-skin over surface of ivarble-liole or cell. 
Coincidently with the alteration in size, position, and condition of 
the maggot, and especially on the power of keeping up a constant 
irritation by means of the muscular contraction and expansion of its 
prickly skin, there are changes in the state of the surface of the cell in 
the lower part of the hide, and also of the surface of the passage up 
the warble swelling, which are of the greatest importance to tanners, 
and all connected with sale of hides. At a certain stage, instead of 
the surfaces being torn and raw, or presently, in part, of a glass-like 
smoothness, a distinct pellicle or skin-like membrane begins to form, 
covering the walls of the perforation or warble-liole, and also, and 
continuously with it, the greater part of the surface of the maggot-cell. 
The beginning of March is the earliest date at which I have myself 
found the lining pellicle observably forming, but the date must 
obviously vary with circumstances. 
On the 3rd of March, 1884, Messrs. Hatton, of Hereford, 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 as 
three-eighths of an inch in height of the 
swelling. 
All that I examined had openings on 
Fig. 15.—Section of warble-cell, 
after soaking in water. * 
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. 
At first the channel down through the hide, and the spot where the 
maggot lies below are merely sores or openings caused by the sharp 
mouth cutters of this then almost microscopic grub. These injuries 
* Figure is repeated from p. 10 to save trouble in reference. 
