59 



be seen if very highly magnified. If, however, the stalk 

 is removed from a not over-ripe mushroom, and the latter 

 pla-ced on a sheet of white paper, in the course of a few 

 hours so many spores are shed from the gills that a print 

 of the gills is produced on the paper. This print consists 

 of myriads of spores which have fallen like dust from the 

 gills. The spores are the reproductive cells of the fungus 

 and, falling to the ground, they grow out to produce tiny 

 filaments. They soon begm to absorb water and food 

 substances from decaying vegetable matter in the soil and 

 manure, and so the vegetable life of the plant is carried 

 on. 



Many fungi are much more minute than the mush- 

 room, nideed are so small that they can only be pro- 

 perly studied under the microscope. As an example of 

 such a fungus we have Mice or, the common white mould 

 which often appears on damp bread or dung. If a piece 

 of bread is kept moist for a few days under a bell-jar 

 in a w^arm place the mould soon appears as a dense 

 growth of fungus covering the surface of the bread. Erect 

 silky threads stand up from the surface like a miniature 

 forest. Microscopic examination shows that the fungus 

 consists of two sorts of filaments : fine ones w^hich branch 

 and ramify in all directions forming a felt on and in the 

 substratum, and the coarser erect ones which stand free. 

 The finer netw^ork on the substratum is the vegetative part 

 of this fungus, while the erect coarser aerial threads are the 

 reproductive organs. The individual branching filaments 

 are very similar to those described for the mushroom, ex- 

 cept that in this case there are no cross walls dividing up 

 the tubes. When the aerial filaments ha^^e grown for a few 

 days there appears at the extreme tip of each a minute 

 round swelling like an inflated ball about the size of a pin 

 head. The protoplasmic contents of this globular body or 

 spore-case soon become divided up to form a large number 

 of spores, and then it has the appearance of a miniature 

 ball full of shot. As the wall of the spore-case becomes 

 dry it breaks, scattering its spores into the air as a fine 

 dust in all directions; the spores of Mucor and, indeed, 

 of many fungi, are very light and easily carried by the 

 slightest current of air. When placed in water the spores 

 germinate in a few hours, the protoplasm within absorbs 

 water, the spore wall bulges in one place and grows out 

 forming a fine filament which, given suitable food 



