943 



from the under side of the leaf, is abundant on the foliage of the alder 

 in some of our deans. This is also a nursery of young Acari. 



A conspicuous yellow gall near the summits of the stalks of Ga- 

 lium verum, growing on the sea-coast, is also owing to miles. The 

 round fleshy galls of this plant are caused by the larvae of a Cecidomyia. 



Colonies of young mites distort the leaves of Galium Aparine, 

 Lotus corniculatus, Polygala vulgaris, and Campanula rotundifolia, 

 by causing them to assume fantastic shapes, to become discoloured, 

 to thicken, or their margins to roll inwards. The foliage of Galium 

 Aparine is also affected in this manner from the presence of the larva; 

 of Psylla velutina of Foerster, (Verhand. Natur. Vereins. Preuss. 

 Rheinlande, 1848, p. 87) ; which appears not to differ from Ps. Galii 

 of the same author. This Psylla produces similar effects on Galium 

 palustre and G. uliginosum ; and it lives likewise upon the leaves of 

 Comanim palustre. 



The hoary, rounded, woolly tufts, so abundant in some places at 

 the summit of the shoots of the wild thyme, are also the production of 

 a crowd of young mites, as was first ascertained by Loew, (Dipterolo- 

 gische Beitr. iv. 24). Lightfoot (Flora Scot. i. 318) attributes them to 

 a Chermes {Psylla) ; and Bremi thought they were owing to the larvae 

 of a gall-midge. The two Bauhins considered plants in this condi- 

 tion as a distinct species ; the ' Serpillum vulgare, minus, capitulis 

 lanuginosis,' (C. Bauhini, Pinax, 220) ; ' S. vulgare, capitulis tomen- 

 taceis, candicantibus,' (J. Bauhini, Hist. Plant, iii. 269). Tournefort, 

 however, conjectured that such appearances were owing to the irrita- 

 tion occasioned by some insect pricking the buds (Hist. Planles des 

 Environs de Paris, 149. Paris : 1698). 



I have not had an opportunity of examining lately these white 

 tufts on the wild thyme ; but young specimens that I brought from 

 Northumberland in July, afforded no traces of a gall-midge, to which 

 they had been ascribed by various writers. 



In conclusion, I may mention that T shall feel obliged to any 

 member of the Club for fresh specimens of the following galls, should 

 they ever occur during their researches : — 



Smooth galls on the leaves of the beech. 



Smooth galls on the leaves or buds of the lime. 



Galls on the dyer's green- weed, [Genista iinctoria). 



Galls on the bryony and the box-wood. 



Galls and excrescences on Salix alba, S. purpurea, and S. fragilis. 



Large gall on the stalk of Hieracium sabaudum and Cnicus arvensis. 



