BOTS. 



289 



and seems to cause a great deal of itching or uneasiness. Grooms are some- 

 times alarmed at the appearance of these insects. Their history is curious, and 

 will dispel every fear with regard to them. We are indebted to Mr. Bracy 

 Clark for almost all we know of the hot. 



CUT OP THE BOT. 



c 



a and b The eggs of the gad-fly, adhering to the hair of the horse. 



o The appearance of the bots on the stomach, firmly adhering hy their hooked mouths. 

 The mai'ks or depressions are seen which are left on the coat of the stomach when 

 the bots are detached from their hold. 

 a The bot detached. 



e The female of the gad-fly, of the horse, prepared to deposit her eggs. 

 f The gad-fly by which the red bots are produced. 

 g The smaller, or red bot. 



A species of gad-fly, e, the cestrus equi, is in the latter part of the summer 

 exceedingly busy about the horse. It is observed to be darting with great 

 rapidity towards the knees and sides of the animal. The females are depositing 

 their eggs on the hair, and which adhere to it by means of a glutinous fluid with 

 which they are surrounded (a and &). In a few days the eggs are ready to bo 

 hatched, and the slightest application of warmth and moisture will liberate the 

 little animals which they contain. The horse in licking himself touches the 

 egg ; it bursts, and a small worm escapes, which adheres to the tongue, and is 

 conveyed with the food into the stomach. There it clings to the cuticular por- 

 tion of the stomach, c, by means of a hook on either side of its mouth; and its hold 

 is so firm and so obstinate, that it must be broken before it can be detached. 

 It remains there feeding on the mucus of the stomach during the whole of the 

 winter, and ur.til the end of the ensuing spring ; when, having attained a con- 

 siderable size, d, and being destined to undergo a certain transformation, it 

 disengages itself from the cuticular coat, is carried into the villous portion of the 

 stomach with the food, passes out of it with the chyme, and is evacuated with 

 the dung. 



The larva or maggot seeks shelter in the ground, and buries itself there ; it 

 contracts in size, and becomes a chrysalis or grub, in which state it lies inactive 

 for a few weeks, and then, bursting from its confinement, assumes the form 

 of a fly. The female, becoming impregnated, quickly deposits her eggs on 

 those parts of the horse which he is most accustomed to lick, and thus the 

 species is perpetuated. 



There are several plain conclusions to be drawn from this history. The bofs 

 cannot, while they inhabit the stomach of the horse, give the animal any pain, for 



