Excrescences and Diseases in Plants. 355 



But in some instances this ermine coating appears also on 

 the lateral buds, where no Cecidomyian larvae have ever 

 been, and spreads over leaves quite unconnected with the 

 organs primarily affected. Such plants, at a distance, look 

 as if suffering from mildew, but a closer inspection reveals 

 the agency of colonies of young Acari. 



I owe the sight of an interesting example, of the influence 

 of young mites in transforming buds, to Professor Balfour. 

 It occurred in a twig of Broom. The buds, to the number 

 of nine, were converted into globular, sessile capitula — from 

 the size of a pea downwards — composed of closely compacted, 

 diminished leaflets, rendered hoary by a dense, stiffish 

 hirsuties. The specimen was from the west of Scotland. 



Another remarkable instance of the extensive derangements 

 which they occasion has been furnished by the Helianthemum 

 vulgare. In a large suite of specimens, from a steep, dry 

 bank at Monynut, not only the unexpanded buds are 

 retained in the form of knots, densely covered with hairs, 

 but the entire foliage is often dwarfed, empurpled, and 

 rendered hoary, and even the stem and branches are not 

 free from alteration. In small plants the altered buds and 

 leaves are excessively crowded. When the bud alone is 

 occupied, there is little difference in its appearance from 

 that assumed when the larva of Cecidomyia Helianthemi is 

 the source of disturbance. 



In a dry, barren pasture at Lucky Shiels I found several 

 ill-thriving plants of Geranium molle intensely infested with 

 young mites. When occupying the leaves, these were turned 

 up at the edges, as if about to grasp their little tormentors. 

 The buds also were full of them, and had their functions 

 entirely suspended. 



[This is the continuation of a communication, for the Club, 

 of an article "On some Excrescences, etc., on Plants occa- 

 sioned or inhabited by Mites," that appeared in the Hist. 

 Ber. Nat. Club, Vol. iii., pp. 111-113 (1852), which had 

 disappeared among Dr Johnston's papers, and was recovered 

 by Mrs Barwell Garter some time since. It is mentioned 

 at p. 214 of the same volume, in a letter printed there, 

 addressed to Dr Maclagan (date 1856.) The additional 

 notes complete what I had to say at the time. — J.H.] 



