218 BOT-FLIES. 
that the presence of such bots had a beneficial influence upon 
the digestive functions, The larve, when mature, are of a 
light-yellow color, with spines white at base and dark-brown 
at the tip. They are distinguished from the other bot-fly 
larye by having only one row of spines at the anterior bor- 
der of their segments, of which the tenth one is unarmed. 

SiS 
dh 
§ 
Ar 
\ 
Fig. 179.—Nasal bot-fly. Greatly enlarged. Original. 
They are found only in the pyloric regions of the duodenum, 
and they do not fix themselves to the margin of the anus be- 
fore being evacuated. 
If but few bots occur in the host they are harmless, but 
if very numerous they assuredly cause some pains, and in 
very extreme cases even colic; and where they penetrate 
through the mucous membrane into the body cavity, they 
cause violent inflammation and death. 
REMEDIES: As these larve are exceedingly tough, and 
very difficult to kill even if immersed in fluids that would 
kill all other insects, and as they are well hidden in the 
stomachs of their hosts, all efforts to dislodge them are 
more or less useless. Still some veterinarians claim good re- 
sults with such substances as Bryonia root, 15 to 20: 
grammes powdered and given in half a pint of water; or tar, 
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a 
