GLASGOW SOCIETY OF FIELD NATURALISTS. 163 



uncommon in Cadder Wilderness during June and July, but I have 

 not been able to rear the perfect insect. 



I would like to oflFer one remark upon such galls as those just 

 mentioned, and all cases of rolled and folded leaves or their mar- 

 gins, and the superficial resemblances which they bear to similar 

 rollings and foldings formed by Lepidopterous insects like the 

 Tortricidae ; for I believe them to be formed in completely differ- 

 ent ways. With the Lepidoptera the leaf is rolled or drawn, and 

 held together by silken threads spun by the larva. With the 

 Cecidomyidse it is, I think, due to an arrestment, partial or com- 

 plete, of the unfolding of the young leaf, brought about in some 

 way by the larva. Certainly, so far as my observations go, they 

 do not draw together the parts of the leaf with threads of silk like 

 the Lepidoptera. All the galls which I have examined bear out 

 the supposition, and are plainly the retention, more or less, of the 

 foldings they had in the bud or when unfolding. Take the rolled 

 margins of the leaves of the Viola canina and Hieracium Pilosella : 

 in the unfolding bud they are naturally rolled involutely ; and the 

 leaf of Salix viminalis has a folded mai-gin when young. Again, 

 all examples of folded leaflets as the clover, wild rose, &c., are so 

 folded in the bud. I think it right to mention that Mr, Mtiller 

 (" Ent, Mo. Mag." VII. 88) states that he found eggs in certain folds 

 of oak leaves. This seemingly militates against the supposition 

 that the larva causes the arrestment. I therefore at present merely 

 throw it out as a suggestion. Possibly also the Lepidopterous larva 

 may have the faculty of arresting the unfolding in addition to its 

 usual methods. 



As to the rearing of the insect from the gall and its preserva- 

 tion for the cabinet, the suggestions given by Mr. Cameron in his 

 paper on the Oynipidae apply equally to the Cecidomyidse. The 

 perfect insects, however, appear sorry objects in the cabinet, their 

 bodies shrivelled up, often with their colours gone or changed into 

 uniform browns or blacks — mere shadows of their former beauty. 

 This necessitates descriptions of the midge to be made while in a 

 fresh state, those taken from the dried insect being almost, if not 

 altogether, valueless. To the intending student of the Ceci- 

 domyidse the following works are indispensable: — Bremi, "Bei- 

 trage zu einer Monographie der Gallmiicken/' 1847; Loew, "Die 

 Gallmiicken," 1850; and Winnertz, '-Beitrage zu einer Monogra- 

 phie der Gallmucken," 1853. 



