232 Linnaan Society. 



been ably discussed by Baron Walckenaer and M. Audouin. Among 

 the Beetles is a weevil, named by Fabricius Attelabus Betuleti (Rhyn- 

 chites of Schbnherr and other authors), which occasionally produces 

 very extensive mischief to the vines of Burgundy, while in England 

 its attacks are limited to the birch. During a residence at Genoa 

 in June last, Mr. Curtis was obligingly taken to the Botanic Garden 

 by M. Mussino to see alive the Chrysomela Americana, L., which 

 inhabits a species of lavender, and his attention was called to the 

 vines against the walls, which were attacked by the mildew, so widely 

 spread during the past summer through Medoc and the wine-growing 

 districts of France and Italy, and especially in Tuscany and Piedmont. 

 While examining this mildew, he perceived many of the leaves of 

 the vine rolled up like cigars ; but the elaborate memoir of M. Debey 

 on Attelabus Betulcc, L., renders it unnecessary to enter into detail 

 on the wonderful mode in which these little animals generally cut 

 and roll the leaves with mathematical precision. It is necessary, 

 however, to state that the female weevil cuts the leaf through across 

 the diameter, without dividing the midrib, then deposits an egg or 

 two upon the upper surface, and subsequently rolls up the lower 

 portion, leaving the upper part untouched, so that it remains green, 

 and the leaf does not fall off for a considerable period, often probably 

 until the tree sheds its leaves. In her mode of manipulation, how- 

 ever, the Attelabus Betuleti seems to differ from the A. Betulce and 

 most other weevils, inasmuch as the author observed, on cutting 

 transversely, that the entire leaf appeared to be rolled up, from the 

 base to the tip. 



Mr. Curtis's principal object, however, in bringing the sub- 

 ject before the Society, was to call attention to a memoir by 

 Prof. Filippi of Turin, published in the ' Nuovi Annali delle Scienze 

 Naturali di Bologna' for January and February 1852, entitled " Storia 

 Genetica di un Insetto Parasito delle Uova del Rhynchites Betuleti," 

 a notice of which is given in the ' Annals of Natural History ' for 

 June of the same year. 



Read also " Pvemarks on the so-called Eye-spot of the Infusoria 

 and Microscopic Alffce." By Arthur Henfrey, Esq., F.R.S., F.L.S. &c. 



Mr. Henfrey states, that in the' "course of an extensive series of 

 observations on the microscopic Algae, especially in investigations of 

 the effect of reagents upon the tissues and contents of the cells, he 

 has frequently been completely baffled by the uncertainty which 

 presented itself as to the real existence of colours exhibited by 

 objects. The decomposition of light taking place in these minute 

 bodies under high magnifying powers is such, that even with 

 lenses most carefully corrected and fully sufficient for all general 

 purposes of investigation, we are left altogether in doubt as to 

 whether or not the phenomena of colour arise from refraction. 

 He uses lenses made by Ross about eight years since, a quarter 

 and an eighth of an inch, the latter of excellent denning power, 

 and is convinced that these are not inferior to any glasses in use on 

 the continent. But with them, particularly the latter, delicate 

 membranes seen edgeways exhibit a blue tint, under certain cir- 



