MOULDS— HYPHOMYCETES 283 



leaves are blotched with white. Can we answer the question 

 satisfactorily and confidently as to how the continuance of the 

 parasite has been secured? It is possible that a perennial 

 mycelium within such of the plant's tissues as have survived 

 the winter may be a sufficient cause, but it is doubtful whether 

 this is the only method in which the perpetuation of the 

 Ramularia has been assured. If it should be contended that 

 the decaying leaves and petioles of the previous year must 

 contain the germs of the parasite, and that the young leaves 

 are infected thereby, this only removes the difficulty a step 

 further, for it has to be shown in what form the germs have 

 been preserved, as it must have been by some form of resting 

 spores or a resting mycelium capable of producing germinating 

 bodies. This is one of the problems which is left for the 

 future to solve. 



So many of the Mucedines and " black moulds " have been 

 ascertained to have relationships with the higher Fungi that it 

 is impossible to do more than briefly allude to a few. In the 

 genus Oidium a number of the species are the conidia of species 

 of the Erysiphei, such as Oidium leucoconium, the rose mildew, 

 of Sphaerotheca pannosa ; Oidium erysiphoides of Erysiphe 

 Martii ; Oidium monilioides of Erysiphe graminis. The 

 common fruit mould Aspergillus glaucus has the reputation of 

 being the conidia of Eurotium herbariorum. Some of the 

 species Botrytis, of the subgenus Polyactis, are the conidia of 

 small species of Peziza, such as Sclerotinia sclerotiorum. The 

 bright yellow mould Sepedonium chrysospermum, which attacks 

 decaying Boleti, and converts them into a mass of golden 

 powder, develops Hypomyces chrysospermum, one of the 

 Sphaeriaceae, of which the mould constitutes the conidia. If 

 we investigate the British species of this genus Hypomyces? 

 we shall find that all have their conidia in some of the moulds. 

 As, for instance, Verticillium agaricinum of Hypomyces 

 ochraceus, and Verticillium lactescentium of Hypomyces 

 terrestris ; also Verticillium microspermum of Hypomyces 

 broomeanum ; Diplocladium penicilloides of Hypomyces 

 awrantius ; Diplosporium album of Hypomyces violaceus, etc. 

 The same kind of association prevails also amongst the 

 1 Monograph of British Hypomyces, by C. B. Plowright. 



