3o6 Mr. ClarkV Obfervation$ on the Genus OcJlrus» 



I at firft fuppofed were loofened from the hairs by the moiflure of 

 the tongue, aided by its roughnefs, and were conveyed to the fto- 

 niach, where they were hatched ; but on more minute fearch I do not 

 find this to be the cafe, or at leaft only by accident ; for when they 

 have remained on the hairs four or five days they become ripe, after 

 which time the (lighteft apphcation of warmth and moifture is 

 fufficient to bring forth in an inftant the latent larva. At this time, 

 if the tongue of the horfe touches the egg, its operculum is thrown 

 open, and a fmall active worm is produced, which readily adheres 

 to the moift furface of the tongue, and is from thence conveyed 

 with the food to the ftomach. If the egg itfelf be taken up by 

 accident, it may pafs on to the inteftinal canal before it hatches; in 

 which cafe its exiftence to the full growth is more precarious, and 

 certainly not fo agreeable, as it is expofed to the bitternefs of the 

 bile. 



I have often, with a pair of fciffars, clipped off fome hairs with 

 the eggs on them from the horfe, and on placing them in the hand, 

 moiftened with faliva, they have hatched in a few feconds. At 

 other times, when not perfe£lly ripe, the larva would not appear^ 

 though held in the hand under the fame circumftances for feveral 

 hours ; a fufficient proof that the eggs thcmfelves. are not conveyed 

 to the ftomach,. 



It is fortunate for the animals infefted by thefe infe6ls that their 

 numbers are limited by the hazards they are expofed to. I fhould 

 fufpeil near a hundred are loft for one that arrives at the perfeft 

 ftate of a fly. The eggs, in the firft place, when ripe, often hatch 

 of themfelves, and the larva, without a nidusy crawls about till it 

 dies ; others are waflied ofif by the water, or are hatched by the fun, 

 and moifture, thus applied together. 



When in the mouth of the animal they have the dreadful ordeal 

 2 of 



