ANIMAL GALLS. 407 



and a littlo 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 

 Enteriaining Knoifhdge, 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," says Kirby and Spence, " is 

 performing the operation of oviposition, the animal 

 attempts to lash her ofi" as it does other flies, with 

 its tail;""]' 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, "J 

 but with the two facts mentioned above from 

 Rtaumur, as v/e!l as with common observation. If 

 the ox then do not attempt to lash ofl' 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 (Gasttroj)hihis equi, Leach), 

 which produces the maggots well known by the name 

 of bolts in horses, is ascertained beyond a doubt to 



^ I.innEeus, Flora Lapponica. P. 378, ed. Lond. 1792. 



•f Kirby and Spence, Introd. i. 151. J Ibid. p. 149. 



