DISEASES OF THE DIGESTIVE ORGANB. 169 



crouchments. They burst their prison-house, and hence are found 

 in the abdominal cavity; and when there, they may be said to 

 have jumped from the "frying-pan into the fire !" Open a horse 

 immediately after death, and, provided his stomach be in a healthy 

 condition, we shall find that the bots have not penetrated leyond 

 the cuticular coat of it; but if he shall not be examined until some 

 Uouis have elapsed, the bots may be found to have passed through 

 the walls of the decomposed stomach and its peritoneal tunic. 



We can imagine, also, that a large number of bots might con- 

 gregate at a given point in the stomach of a horse, and, aided by 

 disease, occasion a loss of continuity in the fibers of that organ; 

 then, on the slightest distension by wind, its walls might be rup- 

 tured and its function paralyzed, and thus the bot be involun- 

 tarily driven from its home, to seek shelter and food in another 

 location. 



We contend that the stomach of a horse is the natural habita- 

 tion of the bot during its minority, and, at the proper season, the 

 digestive canal is the usual channel for its introduction into the 

 external world ; and if these parasites are ever found in any other 

 situation within a horse's body, they are there by the force of cir- 

 cumstances, owing to disease or rupture of the stomach, or from 

 some morbid condition in the gastric fluids, which arouses a set 

 of involuntary actions in response to a stimulus; because, during 

 the whole period of their minority, that is, the larveal state, (a 

 term which, in the language of entomology, applies to the bot from 

 the time of emerging from the egg, or nit, up to that period when 

 it vacates the horse and assumes the form of a gad-fly), they are 

 in the same condition as a new-born babe or an idiot — the one 

 imbibing its mother's milk, and the other performing unnatural 

 antics, both appearing to lack that train of mental operations 

 which implies knowledge, motive, or the consequences resulting 

 from such actions. We very much doubt if the bet can, at any 

 time, by voluntary act, vacate the body of the horse. Reaaon- 

 ing from analogy, we are led to the conclusion that the result 

 is accomplished through their instinctive properties, which are 

 ermmon to many insects and parasites — a perfect adaptation of 

 iL2ans to an end — by which they perform a certain set of opera- 

 tions without choice, ])urpose, or intention of their own, yet, in 

 many cases, producing results which man, through the aid of hia 

 superior intellect, has not been able to surpass. 



