io8 Chapters in Modern Botany CHAP. 



and yellow rattle (Rhinanthus), which are undoubtedly 

 root-parasites, appear also to depend upon the humus of 

 the soil ; the Gfs3#Bchfonotropa Hypopitys is said to be a 

 parasite in the pine woods, but a saprophyte on the rotting 

 leaves under other trees ; and some of the epiphytes gather 

 so many decaying leaves around their roots that it is likely 

 that some of them should also be called saprophytes. The 

 staghorn - fern (Platycerium), so commonly grown as a 

 suspended ornament of our greenhouses, may here again 

 be an instructive case (see p. 99). 



Parasitic Fungi. Of infinitely greater importance as 

 mischief-makers in the world than the parasitic flowering 

 plants are the innumerable parasitic Fungi. Those which 

 cause mildew, potota-disease, some diseases of cereals, vine- 

 plants, and timber-trees, and so on, are often disastrous to 

 the prosperity of a fertile region, nay, as modern experience 

 as well as history too often tells, to a province, a whole 

 nation. Nor do they affect plants alone, but also animals, 

 and even man himself; witness respectively salmon-disease 

 and ringworm. 



Fungi being, like dodder, toothwort, and broom-rape, 

 plants without any chlorophyll, they are unable to use the 

 carbonic acid gas of the air, as green plants do, and are 

 therefore dependent upon ready-made supplies of organic 

 matter. Hence we find them living either as parasites on 

 living plants and animals, or as saprophytes on decaying 

 organisms, or in some cases indifferently on either. 



As we do not propose here to do more than indicate the 

 part played by fungi in the economy of nature, either in 

 destroying living organisms or in utilising the products of 

 decay, we refer the student to that convenient and in- 

 teresting introduction to the subject supplied by Professor 

 Marshall Ward in his little volume on Timber and some of 

 its Diseases (Nature Series, Lond. 1889), and for syste- 



