FUNGI 189 



provided with hairs or wings to carry them in winds, and 

 many float in the water in order to be widely scattered ; but 

 the spores of the fungi are so light and small that they float 

 invisible in either air or water, and so they far outstrip in dis- 

 tribution the best devices of the higher plants. As a result, 

 while the flora of seed plants is very different in different 

 countries, the molds and mushrooms, yeasts and bacteria, are 

 more likely to be the same species the world over. 



Compare seeds and spores as to size and numbers pro- 

 duced. For spores use the dust from a patch of mold and 

 from a puff ball, and try to see, feel, smell, and taste them. 

 The finger tips may be black or green with millions of mold 

 spores, but how much can we feel them? We can see the 

 cloud of " smoke '' from a puffball, but as the spores scatter, 

 can we see them in the air (unless in a ray of sunlight in a 

 darkened room), and have we ever tasted them in food ? 

 Some people enjoy the tastes of certain molds and bacteria in 

 cheese, Camembert, Roquefort, Stilton, Lim burger, and 

 they may be as wholesome as any other vegetable. How do 

 the different kinds smell ? How many spores may we be 

 breathing in with every breath in a musty room ? How does 

 the number of seeds of a grain plant or weed compare with 

 the spores produced by a puffball ? 



Size and power of growth. A baby grows to double its 

 weight at birth in five months. A yeast plant or bacterium 

 may double in size in twenty or thirty minutes. The fungus 

 thus has from seven to ten thousand times the power of growth 

 of the baby. Why this difference ? 



Food, again, is the basis of growth. To dissolve, digest, 

 absorb, circulate to every part of a large body, assimilate 

 (that is, build over the foreign matter into the particular pro- 

 toplasm of the species) are slow and laborious processes. Solu- 

 tion of food substances, especially the proteins (white of egg, 

 gluten, casein, lean meat), is difficult, and absorption through 



