34Q 



Crossland : Fungus Foray at Cadeby, 



There is a considerable amount of evidence in favour of 

 the supposition that the most primitive section of Agarics, as 

 Coprinus, etc., had dark-coloured spores, and that the sequence 

 of evolution of the various colour-groups passed respectively 

 from black, through purple, brown, and pink, to white. During 

 this sequence of evolution certain other features of advantage 

 were evolved as superior means of spore dispersion, protective 

 features, etc. 



Is it possible that, having secured the advantages mentioned, 

 along with others, that a retrogression in favour of coloured 

 spores, which may have some value when combined with the 

 other advantages previously acquired, is in progress ? It may 

 be added that all the genera showing a tendency to form a new 

 series of colour-sections of spores, belong to the most highly 

 organised or white-spored section of Agarics. — G. M. 



Some very striking object lessons illustrating plant diseases 

 caused by fungi were observed in both Melton and Potridings 

 Woods. In the former the Birch trees have suffered severely 

 from the attacks of the Birch-tree Fungus (Poly poms betitlinus), 

 many of them being killed outright long before reaching their 

 prime. Numerous great chunks of the fungus were to be seen 

 which had been allowed to develop and propagate a new genera- 

 tion of disease. Certainly a dead Birch-trunk bearing several 

 large specimens of this fungus is a most interesting object from 

 an artistic point of view, a fact duly recognised by Mr. A. Clarke, 

 who devoted considerable attention to these and other effective 

 groups of fungi, illustrations of which will, in due time, supple- 

 ment the already extensive and unique collection of stereo- 

 photographs of fungi possessed by this enthusiastic mycologist. 

 In other places Fomes annosus Fr. (= Trametes radiciperda 

 Hartig) was specially abundant, but will probably soon be rarer 

 in the district, as the great majority of conifers ate already 

 infected; Sequoia gigantea was in one instance observed to be 

 attacked by this fungus. The Larches were fairly free from the 

 destructive Peziza Dasyscypha calyciua = P. Wilko??iii. One or 

 two cups only were found on a fallen twig. Nearly all the Yew 

 trees in the district were attacked by Sphcerella taxi Cooke. 

 Many trees had been killed by this parasite, which infests the 

 leaves, others were more or less injured ; some of those in 

 the churchyard at Cadeby had been severely pruned back- in 

 the hope of getting rid of the unwelcome pest, but without avail. 

 On careful examination the ascospores of SphcErella taxi prove 

 to be 3-septate, hence the species must stand in future as 



Naturalist, 



