J. SAUNDEES — WITCHES BROOMS. 



75 



were, however, found to he infested with mites, many of which 

 were so minute as to he scarcely discernible with a pocket-lens. 

 In this instance the abnormal i^rowth was prol)ably caused l^y the 

 presence of these insects, or if due to gnarling, then the crowded 

 condition of the twigs rendered them peculiarly susceptible to the 

 attacks of the minute creatures. A similar occurrence had been 

 obsei*ved two days previously on a large beech-tree at Chaul End. 

 A dense growth of weak twigs had developed on the main stem 

 where the principal branches were given oft'. These twigs and 

 the leaves upon them were swarming with mites, but wliether 



Fig. 1. — Erect brooiu uu II<jiiibcaiu [(Jiuptnn.s Jictiilus, L.). Stockwood Park, 

 Luton. Photographed by Mrs. A. Staddon. A foot-nxle (30"5 cm.) is beneath it. 



this growth was due to gnarling, or to the irritation set up by 

 the multitude of parasitic insects, it is difficult to determine. 

 The Ijalance of evidence favours the latter assumption. When 

 present the mites hyl^ernate in the terminal buds, and as they 

 divert the nutritive element, atrophy of branches is the result. 



A very old Witches' Broom occurs on a distoi'ted hornbeam in 

 a hedgerow by the side of the road which leads from Wheat- 

 hampstead to the Bowhng Alley, Harpenden, Herts. It has 

 the appearance of having been caused by a Taphrina. It was 

 floirrishing in May, 1904. 



