(ESTBUS BOVINUS. 203 



for I was not certain, indeed apprehended after such authority 

 that the same species inhabited both animals as Linnaeus 

 had stated. 'Habitat intra Bourn dorsum, in ventriculo 

 Equorum saepe ipsis lethalis.' Lin. Sys. Nat., p. 969. This 

 insect was not known to Linnaeus, and, indeed, has been 

 rarely seen ; Vallisneri, after years of labour, procured only 

 one mutilated specimen of it; and Reaumur, after great pains 

 and expense, only two or three. A mode of obtaining this 

 fly, which succeeded with me perfectly well, I shall now 

 describe, by which I obtained out of three larvae two perfect 

 flies, one so perfect, that it flew away while I was making 

 some experiments in presenting it with different objects; the 

 other I gave to Thomas Allen, Esq., after drawings had been 

 made from it for the use of the Linnsean Society. One I also 

 fortunately caught of these flies, between Salanche and 

 Bonneville, in Savoy, flying in the road, and settling on 

 some dung where cattle had recently passed; this specimen, 

 on my return through Germany, I presented to the vener- 

 able and worthy Professor Daniel Schreber, of Erlang, the 

 intimate friend and pupil of Linnaeus, who till then had not 

 seen it. 



"The following is the simple means for obtaining them per- 

 fect, which may be not unacceptable to those who for their 

 cabinets or from curiosity may wish to see them : 



"During the latter months of the summer, about which 

 time the larvae are found fully grown, and about to quit their 

 habitations, which can be known by the superior size of the 

 abscess, and especially the increased diameter of the external 

 opening; such being selected for the experiment, we re- 

 move the hairs round the tumour to a considerable distance 

 with a pair of scissors as close to the skin as may be; and a 

 piece of leather, thickly spread with pitch, being provided, 

 through the centre of which a hole is cut about the size of 



