Flowerless-Plant Study 



721 



minute objects, the spore-cases being the little white globes, not larger 

 than the head of a small pin which we see upon mold, yet each of these 

 spore-cases breaks and lets out into the world thousands of spores, each 

 one ready and anxious to start a growth of mold and perfectly able to do 

 it under the right conditions ; almost any substance which we use for food, 

 if placed in a damp and rather dark place, will prove a favorable situation 

 for the development of the spore which swells, bursts its wall and sends 

 out a short. thread. This gains nourishment, grows longer and branches, 

 sending out many threads, some of which go down into the nutritive 

 material and are called the mycelium. While these threads, in a way, act 

 like roots, they are not true roots. Presently the tip ends of the threads, 

 which are spread out in the air above the bread or other material, begin to 

 enlarge, forming little globules; the substance (protoplasm) within them 

 breaks up into little round bodies, and each develops a cell wall and thus 

 becomes a spore. When these are unripe they are white but later, they 

 become almost black. In the blue mold the spores are borne in clusters 

 of chains, and resemble tiny tassels instead of growing within little 

 globular sacs. 



Molds, mildews, blights, rusts and smuts are all flowerless plants and, 

 with the mushrooms, belong to the great group of fungi. Molds and 

 mildews will grow upon almost any organic substance, if the right condi- 

 tions of moisture are present, and the temperature is not too cold. 



Molds of several kinds may appear upon the bread used in the experi- 

 ments for this lesson. Those most likely to appear are the bread mold- 

 consisting of long, white threads tipped with white, globular spore-cases, 

 and the green cheese-mold which looks like 

 thick patches of blue-green powder. Two 

 others may appear, one a smaller white mold 

 with smaller spore-cases, and a black mold. 

 However, the bread mold is the one most 

 desirable for this lesson, because of its com- 

 paratively large size. When examined with a 

 lens, it is a most exquisite plant. The long 

 threads are fringed at the sides, and they pass 

 over and through each other, making a web 

 fit for fairies a web all beset with the spore- 

 cases, like fairy pearls. However, as the spores 

 ripen, these spore-cases turn black, and after 

 a time so many of them are developed and 

 ripened that the whole mass of mold is black. 

 The time required for the development of mold 

 varies with the temperature. For two or three 

 days nothing may seem to be happening upon the moist bread; then a 

 qu^er, soft whiteness appears in patches. In a few hours or perhaps 

 during the night, these white patches send up white fuzz which is soon 

 dotted with tiny pearl-like spore-cases. At first there is no odor when the 

 glass is lifted from the saucer, but after the spores ripen, the odor is quite 

 disagreeable. 



The special point to teach the children in this lesson is that dryness and 

 sunlight are unfavorable to the development of mold; and it might be 

 well to take one of the luxuriant growths of mold developed in the dark, 

 uncover it and place it in the sunlight, and see how soon it withers. The 



Bread mold, enlarged. 



