i70 DADD’S VETERINARY MEDIVINE AND SURGERY 
Persons who have paid any attention to the study of physiology, 
are aware that these instinctive or involuntary movements, per- 
formed without consciousness, are the birthright of a vast number 
of tLe inferior orders of creation; therefore, it is not likely thay 
the bot would, even if he possessed the power, voluntarily vacate 
a location favorable to its growth and development. 
Veterinary surgeons have long since discarded the absurd notion 
that bots are the cause of any vain or suffering to horses. In fact, 
some of the most distinguished of them assert that these littlu 
creatures, with their rough exterior, are rather beneficial than 
otherwise, and that, by friction and irritation, they arouse the 
sluggishness of the stomach, and thus promote digestion. Per- 
sons unacquainted with these facts are, therefore, apt to attribute 
effects, during life, to causes which happen after death, and, conse- 
quently, the poor horse has to be dosed with all sorts of nostrums. 
So popular has been the belief that bots are injurious to horses, 
‘and, therefore, must be expelled at all hazards, that almost all the 
old works on farriery contained some favorite recipe for their ex- 
pulsion. Popular opinion, too, has been so much in favor of the 
theory, that Mr. Percivauu thought it his duty, as a publie 
teacher, to make use of the following language: 
“You may boldly assert that bots are in nowise injurious. Still, 
you can not persuade the world so, and, therefore, you must be 
prepared to meet the complaints of those unbelievers, who will, 
now and then, declare that their horses have bots, which must be 
got rid of. But I know of no medicine that has the power of 
destroying; and even if we possessed such, I am not sure that we 
could, even when dead, detach them from the cuticular coat of the 
stomach, to which they are attached by small horns.” 
In allusion to the parasites which infest the human body, Wat- 
son remarks: 
“Tt is a curivas fact that numerous parasites do crawl over the 
surface of our bodies, burrow beneath our skin, nestle in our en- 
trails and riot and propagate their kind in every corner of our 
frame, producing ofttimes such molestation and disturbance as ty 
require the interference of medicine. Nearly a score of animals 
that have their dwelling-place in the interior of the human body 
have been already discovered and described, and scarcely a tissue 
or an organ but is occasionally profaned by their inroads. Each, 
ele, has its special or its favorite domicile. One species cnooses 
