STUDIES OF SPORE-PLANTS 



253 



mycelium will grow in all 

 directions until an entire 

 loaf of bread is interlaced 

 with the hyphae. At the 

 same time the hyphae secrete 

 digestive substances which 

 digest to a soluble form 

 starch and other foods in 

 the bread. These digested 

 or dissolved foods are ab- 

 sorbed by the hyphse and 

 used for growth. The mold 

 is therefore a saprophyte 

 (98). 



The delicate threads seen 

 above the surface of the 

 bread are called erect or 

 aerial hyphas; they are 

 branches of the mycelium. 



FIG. 79. Black mold, 

 aerial hyphse (a.hy), 



(spg). B, immature spore-case. C, mature. D, 

 liberating spores (sp). F, spores. G, H, germi- 

 nation of spores to form new mycelium. (From 

 Parker.) 



FIG. 78. A black mold plant formed from 

 one spore in center. One mature aerial 

 hypha with spherical spore-case (s), and 

 two immature ones. Root-like structure 

 is mycelium. (From Rny.) 



Close examination with a strong hand- 

 lens will show that 

 the color of the mold 

 is due to bodies at- 

 tached to the ends, 

 of the erect hyphas, 

 These bodies are the 

 spore-cases, or spo- 

 rangia, which are 

 filled with spores. 

 The purpose of the 

 aerial hyphae ap- 

 pears to be produc- 

 tion of the spore- 

 cases and elevation 

 of them so that wind 

 currents may better 

 distribute the spores. 

 It is easy, with a 

 low-power micro- 

 scope, to find various 

 stages in the de- 

 velopment of the 

 spore-cases which 



A, mycelium (my) with two 

 each forming a spore-case 



