302 The Scottish Naturalist. 



/ i 



dwell. Common in Glen Gairn. (f) Rosette-galls, formed 

 by Cecidomyia rosaria, occur not uncommonly on S. caprea, 

 near Aberdeen. They are at the ends of the twigs, and 

 consist of a kind of rosette of leaves, which differ from ordi- 

 nary leaves in being sessile and crowded together, forming 

 a noticeable mass, which is still more easily detected in 

 winter, as the leaves of the rosette remain on long after all 

 the other leaves have dropped off. On section, it is found 

 to consist of overlapping leaves, in a bell shape, having at 

 the base a cavity filled closely with hairs, in which live 

 larvae (one or more), (g) Twig-galls consist of swellings on 

 the twigs, more or less distinct, and varying from J' to J ' 

 long, and i' to £' across. Externally, they are (when dry) 

 naked, slightly ridged longitudinally, and brown in colour. 

 They are woody and thick-walled, but consist of soft fozy 

 tissue, and are polythalamous, each cell being inhabited by 

 one larva of Cecidomyia. Sent me from Glasgow by Mr. 

 Cameron ; occurs also in Aberdeenshire. ( h) Consists of 

 Bean-galls on the leaves, resembling in general structure the 

 galls of Nematus gallicola on Salix alba, but they project 

 rather less from the leaf, and are always green. Common 

 at Fyvie, July, 1873. 



Salix aurita L. — On this willow I have found galls, near 

 Aberdeen and at Braemar, which resemble others just de- 

 scribed on S. caprea so much as to make it useless to 

 describe them specially again. They resemble (c), (e), (f), 

 of S. caprea. 



Salix cinerea L. — (a) Rosette -galls, occur commonly near 

 Aberdeen, and resemble almost exactly those of S. caprea 

 (f). They are also common near Dunkeld and in Suther- 

 land, (b) Galls of Nematus pcdnnculi H., occur abundantly 

 from Perthshire northwards to Orkney. They are pea-sized, 

 rounded, and are thickly covered with woolly hairs, (c) 

 Twig-galls. These consist of swellings of various degrees 

 (in the twigs) which I have never seen very large. They 

 are most readily detected after the escape of the gall midge 

 ( Cec. salicis Schranck ?) by means of the round hole of exit. 

 Dunkeld and near Aberdeen. 



Salix repens L. — (a) Abundant wherever the willow occurs 

 from Perthshire to Orkney, (b) Similar to (e) Salix caprea, 

 but forms a recess alone on the under surface. Common 

 in August in Glen Gairn. (c) Twig-galls form swellings on 



