THE FUNGI 163 



hyphse ramify over and through the nutrient 

 substratum, and sometimes they cohere in 

 strands. They then become easily visible to 

 the naked eye and are popularly known as 

 " spawn." The spawn thus represents a 

 specially luxuriant condition of the vegetative 

 body or mycelium of the fungus, the mycelium 

 being taken as a collective term for the mass 

 of hyphal threads of which the vegetative part 

 of the fungus is composed. Even the " toad- 

 stools " and other fructifications of fungi are 

 entirely produced by the organised weaving 

 of the hyphae into more or less solid structures, 

 followed by differentiation in the mass thus 

 formed, together with the specialised growth 

 of certain groups of hyphse. 



The fungus obtains the whole of its food 

 from the substratum in which it is growing, 

 and some of the nutriment is always of 

 organic origin. Inasmuch as the fungus 

 contains neither chlorophyll, nor any other 

 material which would enable it to utilise 

 the energy of sunlight, there is no necessity 

 for the growing mass to expose itself to light 

 at all. Indeed, to do so would carry with 

 it the manifest disadvantages of removing it 

 from the immediate source of nutrition, as 

 well as of exposing it to the risk of desiccation. 



Now, having regard to the fact that the 

 vegetative plant of the fungus is absorbing 

 the whole of its food in a dissolved form from 

 the material in which it is ramifying, it will 

 be evident that the larger the surface, in 



