CHAP. I. 



OX WARBLE FLY. 



563 



lump at one end. When full-grown the warble-maggot is of the 'shape 

 shown in fig. 139. 



The mischief may first be found on the flesh side of the hide early in 

 the winter. 



Whilst the maggots (fig. 140) are in the warbles, though a skin-like 

 membrane forms round the surface of the perforations (see figs. 141 

 and 142), they cannot heal up because the maggot lies within ; and 

 when the warble-grub has fallen out, though the whole contracts, the 

 surfaces, being already covered with a film of tissue, are slow to unite ; 

 and, as may be seen in warbled hides (figs. 143 and 144), union 

 is often prevented by this skin-like film shelling oft', and lying with 

 dried matter in the perforation. On the under side of the hide, though 



Fig. 144. Portion of Under Side of Warbled Hide, after being Tanned. 



the surface may not be broken, yet the subcutaneous tissues are often 

 left as a mere film of no strength, which injures the surface of the 

 leather. 



When the maggot is full-grown it is about an inch long and dark grey ; 

 it presses itself out of the opening tail foremost, and falls to the ground, 

 where it finds some shelter, either in the ground or under a stone or 

 clod, and changes to a chrysalis. The chrysalis is dark brown or 

 black, much like the maggot in shape, only flatter on one side ; and 

 from this brown husk the warble-fly comes out in three or four weeks, 

 but this length of time is increased by cold weather. 



With regard to methods of remedy, there does not appear to be any 

 difficulty of getting rid of the warble-maggot easily and cheaply, when 

 the warble has " ripened " that is, opened so far that the black end 

 of the tail is visible. Then it may be destroyed cheaply and quickly. 

 From special observations, taken during the last three years, it has 



002 



