76 J. SAUNDERS — witches' BKOOMS. 



Welimer, in ' Bot. Zeitung,' 1896, discusses the formation of 

 these Witches' Brooms (' Diseases of Plants,' Tu])euf , p. 163, 

 foot-note) . 



Hazel (Corylus Avellana,!!.). — Examples of Witches' Brooms 

 were observed in April, 1904, on several hazels on the Lynchets 

 at Chalk Farm near Caddington. The aspect of the position is 

 northerly, which, by reason of diminished sunshine, may render 

 the vegetation more susceptible to disease than if it were 

 southerly. For about a mile on this part of the range of hills, 

 Witches' Bro(mis were numerous on several species of trees, 

 particularly hazel and hornbeam. The hazels are aged and 

 crowded, and the brooms were developed on the ends of the 

 branches. Most of the diseased twigs bore stamiuate catkins, 

 and although not observed at that date they must have produced 

 pistillate tufts also, as upon a subsequent visit in Midsmnmer 

 a few immature nuts were found on them. The catkins and 

 leaf-buds at the time of unfolding were much smaller than those 

 on the healthy branches. All the brooms contained a considerable 

 proportion of dead twigs, and in some cases decay extended for 

 several feet from the extremities of the branch. This is a feature 

 common to most of these growths. The small branches live but 

 a few years, in this respect differing from most of the nonnal 

 ones, which continue to grow indefinitely, their existence usually 

 terminating only with that of the tree which bears them. Upon 

 examining the bushes in the following July it was found that 

 many of the leaves showed brown patches, which upon examina- 

 tion were found to contain both asci and spores ; the latter were 

 ovate and minutely dotted. They were evidently the fniiting- 

 stage of a Tajilirina. 



Spruce Fir {Abies (Picea) excelsa). — In July, 1905, Mr. A. 

 Staddon called my attention to a broom on a spruce fir in Luton 

 Hoo Park (PI. VI). The growth was very dense, the branches 

 were abbreviated, and the leaves were more crowded and 

 spreading than in the type. The foliage was also shorter, 

 averaging 8 to 10 millimetres in length, whilst the normal leaves 

 were 13 to 14 millimetres. 



The tree was examined again on 25th December, 1905. It 

 was then seen that the leaves of 1904 had all withered and 

 many of them were fallen, whilst the foliage of 1905 was green 

 and vigorous. A close examination of the withered 1904 foliage 

 revealed the presence of the fruiting-stage of a fungus, which 

 showed as dark spots, exserted from the stomata. Under the 

 microscope numerous mycelium - threads and light-coloured 

 spherical spores were seen. 



On 14th January, 1905, in a wood at Caddington, another 

 spruce fir was observed which bore a Witches' Broom, very 

 t-'imilar to the one at Luton Hoo. Specimens of this were sent 

 to Mr. W. H. Burrell, who kindly examined the leaves and 

 prepared micro-slides from them of transverse sections. In an 

 accompanying letter Mr. Burrell remarked that " The resin 



