THE STORY OF THE MOULDS 



691 



arises, we may know that fungi or bacteria 

 have made their appearance. A piece 

 of cheese, that is apparently quite sound 

 one day, may on the next de\'elop a 

 mould-covered surface that hourly waxes 

 larger. The explanation is, of course, 

 that the substance of the cheese has 

 reached that stage of ripeness where decay 

 or a dissolution of its chemical equi- 

 librium sets in, and this state gives oppor- 

 tunity for the germination of the mould 

 spore. Hence the necessity for refrigerat- 

 ing or canning 

 articles of food 

 as a means for 

 their preserva- 

 tion. The im- 

 portance of 

 carrying out 

 methods of pre- 

 servation in a 

 thorough man- 

 ner cannot be 

 too much in- 

 sisted on ; the 

 slightest oppor- 

 tunity of attack 

 is immediately 

 seized upon by 

 the enemy. 



On page 6go is 

 shown some of 

 the familiar Blue 

 Mould (Asper- 

 gillus) that deve- 

 lops on cheese 

 magnified 60 

 diameters. In 

 this photograph 



the hyphcB and the spore-bearing branches 

 are clearly seen, and also we observe 

 that innumerable spores are being scat- 

 tered in all directions. Xow I will ask 

 my reader to imagine what happens 

 when the cheese-dish is brought to the 

 table and the cover removed. 



The piece of cheese included in this 

 photograph is scarcely larger than a pin's 

 head, yet numerous spore-heads appear ; 

 on the whole surface of the cheese upon 

 the dish, however, there mav be many 

 thousands of spore-heads. Immediately 

 the dish-cover is removed, the inrush of 

 air causes every ripe head to burst and 

 scatter its spores. In the illustration on 

 this page I have photographed one of the 



differ 

 just as 

 larger 

 t h e 





ONE OF 



Photographed in the act of scattering its spores into the atmosphere. 

 (Magnified 200 diameters.) 



ripe heads in the act of scattering its 

 spores under a magnification of 200 dia- 

 meters, or, more popularly speaking, 40,000 

 times ; probably this picture will explain 

 better than a volume of words how these 

 tiny germs may infest an atmosphere. It 

 is obvious that the air at once becomes 

 loaded with spores, each of which may be 

 the parent of another mould forest. 



In the last picture another mould 

 species is shown, a form that frequently 

 grows upon moist bread or paste. It will 



be seen, there- 

 fore, that these 

 minute fungi 

 in form 

 do their 

 relatives 

 more 

 familiar t o a d- 

 stools and mush- 

 rooms. It is the 

 mycelium of the 

 mushroom that 

 constitutes the 

 " spawn " used 

 for mushroom 

 propagat ion, 

 \\hile the mush- 

 room itself is 

 a n agglomera- 

 tion of the 

 spore- bearing 

 branches or 

 aerial hyphte. 

 such as we have 

 glanced at in 

 the delicate 

 moulds. 

 Unfortunately, the depredations of 

 these minute and lowty organisms ex- 

 tend far beyond our food materials 

 and household commodities. There are 

 numerous forms that attack and thrive 

 upon living plants, eventually bringing 

 about their destruction : indeed, it is 

 probable that every living plant has 

 some species of mould or fungus that 

 preys upon it ; some unfortunate plant 

 hosts are victims to quite a large number 

 of such enemies. 



When the gardener looks grave and 

 talks of mildew, rot. canker, scab, smut, 

 bunt, leaf-curl, leaf-blotch, fungus disease, 

 etc., we may know that the minute but 

 destructive fungi we popularly term 



c^ 



00 



THE RIPE SPORE-HEADS SEEN 

 ILLUSTRATION ON PAGE 690. 



IN THE 



