on the CEstridcB. 73 



June 29. — Received two larvae of hcemorrhoidalis and one of 

 eqiii: after this date I did not obtain any further contribu- 

 tions of larvse which had traversed the intestines of the 

 horse. The whole of them were placed in some damp mould 

 in a garden pot, which was tied over with gauze, and on 

 August 3rd two females o( hcemorrhoidalis came out of pupae, 

 and also a beautiful female of G. veterinus. 

 August 13. — Two male flies of ha^morrhoidalis appeared. 

 August 14. — One more specimen of hcemorrhoidalis came out, 

 being a very fine male, and the valvular openings of its pupa 

 case are not detached, as generally happens with one or both 

 of them. 

 As the number of larvae which completed their transformations 

 corresponds with that of those which were received upon, and 

 after, the 25th of June, and which were all, except two, of G. 

 hcemorrhoidalis, I conclude that those brought on May 12th and 

 16th, and which were nearly all presumed to be G. eqiii, might, 

 in addition to injury from pressure, have passed prematurely from 

 the stomach of the horse, owing to some accidentally disturbing 

 cause ; therefore, the time of these creatures quitting tlieir seat of 

 nurture is about the last week of June, and as they appeared in 

 the fly state from the 3rd to the 14th August, the intervening 

 period was about seven weeks. 



The following entry appears in my journal under date of 

 June 1 : — " Received from Mr. H. two pieces of the stomach of 

 an old horse, which he killed to-day by order of the owner, as, 

 notwithstanding it had been turned out at pasture for some time, 

 it was unable to perform any work." One of the portions, which 

 is entirely of the villous structure of the stomach, contains a 

 cluster of forty-eight larvre of Gast. hcemorrhoidalis, and the other 

 portion, which is half cuticular and the remainder villous, has six 

 larvse attached to the former and twenty-four upon the latter sur- 

 face, in all thirty, of the larger kind of Gast. cqiii ; the whole are 

 nearly full grown and all alive, upon detaching one of them it 

 speedily refixed itself.* The villous portions of the stomach to 

 which the bots fixed themselves are much altered in organization, 

 being generally thickened, somewhat inflamed, and discoloured in 

 patches with blood, several spots are ulcerated, forming cavities 



* In order to keep the parts sweet, and cleanse them from some particles of 

 vegetable matter and a good deal of mucous, they were, in the first instance, and 

 that immediately, put into strong salt and water for a day or two, when it was 

 found that even this pickling had induced but very few of them to relinquish their 

 hold. 



