ANIMAL GALLS. 407 



and a little bent, upon the point of which it holds a 

 small white egg, scarcely so large as a mustard-seed, 

 and when it has placed itself in a perpendicular posi- 

 tion, it drops its egg, which rolls down amongst the 

 hair to the skin, where it is hatched by the natural 

 heat and perspiration of the reindeer, and the grub 

 eats its way slowly, under the skin, causing a bump 

 as large as an acorn."* The male and female of 

 the reindeer breeze-fly are figured in the Library of 

 Entertaining Knowledge, Menageries, vol. i., p. 405. 



There is one circumstance which, though it appears 

 to us to be of some importance in the question, has 

 been either overlooked or misrepresented in books. 

 " While the female fly," say Kirby and Spence, " is 

 performing the operation of oviposition, the animal 

 attempts to lash her off as it dues other flies, with 

 its tail ;"t though this is not only at variance with 

 their own words in the page but one preceding, 

 where they most accurately describe " the herd with 

 their tails in the air, or turned upon their backs, or 

 stiffly stretched out in the direction of the spine,"} 

 but with the two facts mentioned above from 

 Reaumur, as well as with common observation. If 

 the ox then do not attempt to lash off' the breeze-fly, 

 but runs with its tail stiffly extended, it affords a 

 strong presumption that the fly terrifies him by 

 her buzzing (asper, acerba sonans), rather than 

 pains him by piercing his hide ; her buzz, like the 

 rattle of the rattle-snake, being instinctively under- 

 stood, and intended, it may be, to prevent an over- 

 population, by rendering it difficult to deposit the 

 eggs- 



The horse breeze-fly (Gasterophilus equi, Lkach), 

 which produces the maggots well known by the name 

 of botls in horses, is ascertained beyond a doubt to 



* l.mnii'uK, Flora Lappunica, p. 378, ed. I.oiul. 1792. 

 f Kirby anil Speuce, Intiod. i. 151. , Ibid. \\. 119. 



