354 Excrescences and Diseases in Plants. 



white one a larva, which has died before reaching the 

 pupal state. 



WM. GRANT GUTHRIE, 



Hawick. 



[This curious parasite is fully described by the late Mr 

 F. Walker, F.L.S., in Yol. ii., pp. 288-9, " Diptera, Insecta 

 Britannica." On Plate XX., Mr Westwood figured S. 

 pallidum and 5 «, an antenna of S. hirundinis, and fig. b, 

 wing of ditto.] 



Further Observations on Excrescences and Diseases occa- 

 sioned in Plants by Mites. By Dr James Hardy. 



On a former occasion (Ber. Club's Trans., iii., p. Ill) I 

 made some cursory observations on several alterations pro- 

 duced in different species of plants by the larvse of mites. 

 Since then I have met with a few other instances of their 

 operations, which may be worthy of record. 



The leaves of the Sycamore sometimes carry, on the upper 

 surface, a crowd of small stalked, conical, or spherical warts, 

 little larger than pin heads, which arise from a depression 

 on the underside, thickly beset with white hairs in the 

 centre. They are tough and leathery, and form a secure 

 cover for the minute mite larvse which they include. 



In Lotus corniculatus the edges of the leaflets, somewhat 

 thickened, become purple, and densely pubescent ; and some- 

 times a few hollow cups, lined with down, enclose the larvte. 

 Those rufescent, irregularly thickened margins, as well as 

 empurpled and, as it were, inflamed spots often conspicuous 

 on the leaves of Hypochceris radicata, seem also to be owing 

 to the mite larvse that abound upon the foliage. 



In a dwarf state of Epilohium palustre, growing in very 

 wet spots in bogs, the infested leaves twist, and their edges 

 become involute ; and sometimes the plant has its growth 

 arrested, and the distorted leaves form a cluster at the 

 summit. 



A dense, hoary pubescence characterises those buds of 

 Veronica Chamcedrys that envelop the larvse of Cecidomyia 

 Veronicce. These buds are principally the terminal ones. 



