86 RESEARCHES ON FUNGI 



Upon being stirred, the spores became evenly scattered in the 

 fluid. With the counting apparatus, as an average of several 

 trials, the O'l gram of the fruit-body was calculated to contain 

 3,245,000,000 spores. The whole fruit-body, therefore, was calcu- 

 lated to contain 7,500,000,000,000 spores. The fruit-body had a 

 small sterile base and a very thin, although imperfect, peridium, 

 but a small part of the gleba had been lost by accident. Taking 

 these factors into account, it seems fairly safe to state that the 

 puff-ball produced about 7,000,000,000,000 spores, or as many as 

 would be liberated by about 4000 good-sized Mushrooms. Pro- 

 bably a large Giant Puff-ball which, it is said, may sometimes 

 almost attain the dimensions of a sheep, is the most prolific 

 organism living on our planet. 



The foregoing figures will give some idea of the extraordinary 

 activity of a large hymenomycetous fruit-body in producing and 

 liberating spores. It is safe to say that a large Mushroom, 

 Coprinus comatus or Polyporus squamosus, liberates at least a 

 million spores a minute, and keeps up this enormous rate of 

 discharge for several hours or days. 



Since it may be assumed that the number of fruit-bodies of 

 any given species remains fairly constant from year to year, from 

 the foregoing figures we can obtain a rough estimate for the 

 rate of elimination of the spores or young plants by death. If 

 from the spores of a Mushroom of Psalliota campestris only one 

 Mushroom were eventually produced on the average, then, in 

 accordance with the figures obtained, it could be stated that 

 only one spore in about 1,800,000,000 ever manages to develop 

 into a mature plant. However, it must be remembered that 

 each spore may produce a wide-spreading mycelium or spawn, 

 and that this may give rise to a number of fruit-bodies. Doubt- 

 less also, in nature, the spawn is perennial and often lives for 

 several years in turf, &c., so that a plant which has arisen from 

 a single spore must often produce a crop of Mushrooms 

 annually. If, in consideration of these facts, we assume that, 

 when a plant succeeds in producing fruit-bodies at all, it 

 produces altogether on the average ten of them, it may be 

 estimated that only one spore out of about 20,000,000,000 spores 



