BOTS. 209 



A species of gad-fly, c, the oetrus equi, is in the latter part of 

 the summer exceediiig:ly busy about the horse. It is observed 

 to be darting with great rapidity towards the knees and sides of 

 the animul. The females are deposithig their eggs on the hair, 

 and wliich adhere to it by means of a glutinous fluid with 

 which they are surrounded (a and b). In a few days the eggs 

 are ready to be hatched, and the slightest application of warmth 

 and moisture will liberate the little animals which they contam. 

 The horse in hcking himself touches the Qgg ; it bursts, and a 

 small worm escapes, which adheres to the tongue, and is con- 

 veyed with the food into the stomach. There it clings to the 

 caticular portion 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 until the end of the ensuing spring ; when, 

 having attained a considerable 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 bots cannot, while they inhabit the stomach of the 

 horse, give the animal any pain, for they have fastened on the 

 cuticular and insensible coat. They cannot be injurious to the 

 horse, for he enjoys the most perfect health when the cuticular 

 part of his stomach is filled with them, and their presence is 

 not even suspected until they appear at the anus. They cannot 

 be removed by medicine, because they are not in that part of 

 the stomach to which medicine is usually conveyed ; and if they 

 were, their mouths are too deeply buried in the mucus for any 

 medicine, that can be safely administered, to affect them ; and, 

 last of all, in due course of time they detach themselves, and 

 come away. Therefore, the wise man will leave them to them- 

 selves, or content himself with picking them off when they col- 

 lect under the tail and annoy the animal. 



The smaller hot, / and g", is not so frequently found. 



Of inflammation of the stomach of the horse, except from 

 poisonous herbs, v r dmgs, we know little. It rarely occurs. It 

 U 



