76 Mr. W. Sells' Observations 



Part II.— [Read 1 October, 1838.] 



With the return of the proper season this year, I resumed ray 

 attention to the economy of the Gasterophili, and extended my 

 observations to the proceedings of (Estrus hovis, the only species 

 of that genus respecting whicli I was at all likely to be successful, 

 as all my inquiries concerning (Estrus ovis, among intelligent 

 butchers, were answered by saying that since the very general 

 preference of the breed of polled sheep, the maggot formerly 

 found internally near the origin of the horn had become very un- 

 common. 



The Entomological campaign of the current year, as respects 

 the insects under consideration, having now nearly terminated, I 

 beg leave to submit such results of the same, in that department, 

 as are in my hands, to the notice of the Society. 



As regards (he Gasteroph'di, between the middle of May and 

 the end of July, I received many specimens of Hcemorrhoidalis, 

 W'hich made their appearance in the fly state at corresponding dates 

 vip to the end of August. These larvae were chiefly removed by 

 the finger of the collectors from the verge of the anus of the 

 horse, and may thus be easily oblained, while those of G. equi 

 are far more difficult to procure, as they drop with the dung, and 

 are frequently picked up by poultry. I received one specimen of 

 the latter as late as August 8th, which buried itself in the mould 

 nearly two inches, but not having come out has most likely 

 perished. 



On August 27th a fine specimen of G. sahitifems (var. (3 Clk.) 

 came forth, but owing to the vessel which contained it being incau- 

 tiously exposed to a powerful sun before the wings were quite 

 dry, the insect, being very vigorous and active, damaged them 

 considerably during my absence from home. 



I will now give my observations upon (Estrus hovis in a con- 

 densed form, according to the order in which they appear in my 

 journal. 



May 4. — Early in this month I commenced my walks among 

 the farms in my neighbourhood, and visited several dairy 

 establishments, and lost no time in selecting the more promis- 

 ing cases for practising the method recommended by the able 

 author of the Essay on Bots, for the capture of the full 

 grown larva. I had the oestral tumours, at various periods, 

 on several cows, carefully shaved and dressed in the most 

 approved Clarkyan mode, but, although the operation was 

 performed " secundum arteni" with great care, and the plaster 



