CESTRUS, ONISCUS. 227 
From some observations which I have made, ¥ 
am inclined to the following opinion ; but I con- 
fess it wants farther proof. ‘That the eggs depos- 
ited under the skin, near the inner angle formed 
by the horse’s head and neck, are the only CSIs OF 
nits, which produce the bot larva. That when 
they pass into the larva state, they are very small, 
and make their way directly into the alimentary 
canal, and soon grow to size suificient to injure or 
destroy the horse. ‘This bypothesis is more con- 
formable to analogy, if we study the habits of 
other animals, not intestinal, which inhabit the 
bodies of large animals, while in the larva state. 
Ii on further observation this opinion should be 
established, horses may be saved from the mortal 
malady, called the bots, by fastening a piece of 
oil-cloth under the throat, for three or four weeks; 
commencing on or about the last week in August. 
As my observations are confined to one year, I 
would invite all students in zoology to make care- 
ful observations on this insect; and, if possible, 
to hatch out a bot larva, and see whether the ve- 
terinus is, or is not, the only species which causes 
such destruction among the most valuable of all 
animals. 
“See MS. P. 
9—1. Oncutpium. Spee. 1. 
typhe, body convex above, ash-colour, tubercled ; 
flat and smooth beneath. An inch long, or more 
when creeping. 
Sec MS. ?. 
6—2to5. Oniscus. Spec. 43. 
armadillo, (sowbug,) feelers unequal, hind ones 
