6 NATURAL HISTORY 



ing at it, (he raifed her head a little, bending down the 

 hinder part of her body, reclined a little on one fide, and 

 throwing out a fmall fting, pierced the leaf obliquely, and 

 by degrees feparated the upper membrane from the flefhy 

 part of the leaf ; making a circular incifion of about half 

 a line in diameter : then withdrawing the fting a little, 

 forced an egg into the aperture. I marked this leaf, by 

 putting a thread loofely round it, in order to determine 

 the precife time which would elapfe before the egg was 

 hatched. Examining it from time to time with a magni- 

 fier, I found it encreafed in bulk, and from a long oval, 

 approached a fpherical form, as reprefented at fig. i. a. 

 Sc b. 



On the tenth day I could perceive, through the mem- 

 branes of the leaf and egg, the eyes of the larva, as afcjfg^ 

 i. b ; and on the 20th of the month it appeared on the 

 leaf and began to feed. This was the fourteenth day from 

 the depofite of the egg, and the refult accorded with the 

 appearance of the other Slugs that firft (hewed themfelves 

 on the 15th of the month from eggs depofited on the id. 



From the 11th to the 19th the flies appeared in the great- 

 eft numbers, (o that Icaught 50 or 60 in a fliort time while- 

 Handing by the tr.es. They have not the timidity of other 

 infeBs, and may be taken with very little trouble. When 

 the fly is about to place an egg in a leaf, after (he has be- 

 gun to make the incifion, the leaf may even be cut off, 

 and with a magnifier of about 3 4ths of an inch focus, this 

 very amufing operation, which is performed in lefs than 

 a minute, may be diftinftly obferved through the tranf- 

 parent (kin of the leaf. The incifion is generally made 

 on the under fide of the leaf, without wounding the (km 

 of the upper fide ; the egg being forced in raifes the up- 

 per (kin, and the fpot appears like a fmall bhfter ; the 

 health of the leaf and the circulation of its fap, appear to 

 be in no wife injured ; the egg is kept moift, and defend- 

 ed from the action of the air and rain ; but has all the 

 benefit of light and heat. 



The (kin of the egg is foft and fufceptible ofdiftention, 

 and in oiderto nreierve thefe qualities, it feems neceflary, 



that 



