402 VETERINARY LECTURES 



tip; large head and brown wings, black legs and lighter feet.' 

 There seems to be some difference of opinion as to whether the 

 female fly deposits the eggs on or within the skin, or on some part 

 of the body where the animal can reach with the tongue, so that, 

 in the event of the latter being so, the young embryos, after being 

 hatched from the eggs, are carried by the tongue to the mouth, 

 from whence they find their way to the skin on the back, where they 

 develop into warbles. From my own observation, I do not favour 

 this mode of development ; it may be the method, but my own view 

 is that the peculiar pointed end of the eggs are placed by means of 

 the female ovipositor, which is telescoped, within the outer layer of 

 the skin where the embryos are hatched, and which afterwards bore 

 their way into the true skin, and there develop into the larval form or 

 warble. It is strange that the warbles should only be found on the 

 back of the animals between the top of the shoulders and the loins, 

 a place where the beast can neither lick with the tongue nor lash 

 with the tail, and there is no doubt but that pain is produced when 

 the eggs are deposited, which cause the animals to gallop at a 

 break-neck pace all over the pastures, with tails extended and 

 slightly depressed towards the tip, rushing under the shade of the 

 branches of trees, or into ponds and rivers where their tormentors 

 will not follow, and are thereby left at rest ; but it is not until the 

 spring months — as already stated — that the effects are seen, in the 

 shape of the tumours or warbles. Light-coloured animals seem to be 

 more particularly attacked. 



682. On examination of the skin on the back, a dark opening can 

 be seen, surrounded by a small quantity of frothy matter. By 

 pressure with the thumbs on each side the larva can be squeezed out. 

 If not interfered with, in due time the slug comes out of its winter 

 shelter of its own accord. This is accomplished by a wriggling 

 motion, for which its peculiar spiral shape — as depicted in the illus- 

 tration — is specially adapted. It then falls to the ground, and is 

 converted into a chrysalis, and finally into the perfect insect, ready to 

 recommence the cycle of life in the summer months. As warbles 



