DISEASES OF THE DIGESTIVE ORGANS. 169 
ervachments. 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 
hours 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. 
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 sare 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 
frora such actions, We very much doubt if the bet can, at any 
time, by voluntary act, vacate the body of the norse. Reason- 
ing from analogy, we are led to the conclusion that the result 
is accomplished through their instinctive properties, which are 
e-mmon to many insects and parasites—a perfect adaptation of 
means to an end—by which they perform a certain set of opera- 
tions without choice, purpose, or intention of their own, yet, in 
many cases, producing results which man, through the aid of his 
superior intellect, has not been able to surpass. 
