INSECTS. 18T 



the elongated white eggs are fixed separately to hairs. 

 The maggot, elongated when first hatched, perforates 

 the skin, and gets into the subcutaneous connective 

 tissue, where it does not, as a rule, keep to any one 

 place, but wanders here and there, sometimes pene- 

 trating the flesh, or even entering the spinal canal. It 

 always, however, wanders back again later on into 

 the subcutaneous connective tissue, where it gives rise, 

 during the winter or the following spring, to one of 

 the well-known tumours, or " warbles." After fixing^ 

 on a definite spot, it moults, becoming broader, and of 

 a yellowish-white colour. The maggot first causes 

 an increased flow of blood to the part, and then 

 inflammation. An excavation filled with matter is 

 thus developed, and there is gradually formed a con- 

 nective tissue sac communicating with the exterior 

 by a minute tube. In spring, or early summer, the 

 warble, which is visible externally, has reached the 

 size of a pigeon's egg ; the maggot meanwhile becomes 

 first greyish yellow, then brown patches appear, and 

 lastly it assumes a dark brown colour, is an inch long 

 or rather more, and somewhat swollen. It is now 

 ready to pass into the resting stage, crawls out, and 

 lets itself fall to the ground, where, within the 

 larval skin, it becomes a black pupa four-fifths of an 

 inch long, from which, about four weeks later, the fly 

 creeps out. Damage done : If the warbles occur only 

 in small numbers on an animal, its health is not much 

 afiected, though this must undoubtedly be the case if 

 there are many, say fifty, or even up to a himdred, in 

 the same animal. In such cases the yield of milk will 

 be considerably diminished. Holes, too, are present 

 in the skin, which, though they may close again, if the 

 animal remains alive, always leave a thin place. The 

 outer surface of meat from animals infested with 

 warbles is dirty yellow, fiaccid, or even soft and jelly- 

 like (" licked beef ") ; it must be scraped off". Enemies ; 

 Starlings settle, in spring, on the backs of infested 



