FUNGI 



leaves, twigs, insects' bodies, worm-casts, and other manures. 

 The way in which they work is too difficult to explain here, 

 but to get an idea of the romance of the underground world 

 one must try to picture to oneself these swarms and myriads 

 of germs and bacteria all incessantly and busily engaged at 

 their several duties. In the uppermost layers there are prob- 

 ably in a single cubic inch of good soil from 54,000,000 to 

 400,000,000 of these microbes. Many are absolutely 

 necessary to the harvest ; a few may be of little importance, 

 but there are sure to be some of those dangerous sorts which 

 might devastate a continent with disease in a single summer. 



There are also quantities of other fungi. The fairy rings 

 which one sees year after year in widening circles of bright, 

 fresh green are the work, not of fairy footsteps, but of an 

 underground fungus {Marasmius oreades and others). Its 

 threads are thin, white, and delicate ; they attack the roots 

 of glasses, etc., on the outer side of the ring. It is therefore 

 on this outer side yellow, dry, and more or less withered. 

 On the inner side, however, the grass is luxuriant and of a 

 rich bright green. Here the fungus has died off, and its 

 remains, as well as those of the plants which it destroyed, 

 form a rich manure for the new grass following on its track. 

 Every year the ring widens ; at a certain time in summer one 

 sees the irregular line of mushroom-like fungi which are 

 formed by the destructive underground absorbing threads. 

 This, however, is but one of the underground fungi. There 

 are many kinds ; some are useful, others are very destructive. 



Upon the upper surface of the soil there falls not only 

 rain, but another sort of rain consisting of seeds, dead 

 leaves, insects' bodies, fungus spores, bacteria, and dust. 



Every year when the ploughman turns the sod there is a 

 revolution in the whole of these populations. 



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