CHAPTER IV 



THE FUNGI 



THE Fungi are an immense group by far the largest of 

 all the cryptogamic Classes. Up to the present time 

 about 40,000 species have been described. The whole 

 of this vast mass of most heterogeneous forms is 

 distinguished by one physiological character the 

 absence of chlorophyll. Hence all Fungi alike are 

 incapable of assimilating their carbonaceous food from 

 the carbon-dioxide of the atmosphere ; they must obtain 

 it ready made, as it were, from other sources. So far 

 as carbon-compounds are concerned, Fungi are entirely 

 dependent on organic food. This they obtain either 

 directly from other living creatures, on which they prey, 

 or from dead organic substances produced by living 

 organisms. In the former case we call them parasites, 

 in the latter saprophytes. 



Parasitic and saprophytic plants wholly or nearly 

 destitute of chlorophyll occur in other classes of the 

 vegetable kingdom, as members of very diverse families. 

 Thus among flowering plants, for example, we have 

 the Dodder (Cuscuta) and the Broomrape (Orolanclie) as 

 parasites; the Bird's Nest (Mbnotropa) and the Bird's 

 Nest Orchid (Neottia nidus-avis) as saprophytes. In all 

 such cases, however, the parasitic or saprophytic forms 



216 



