384 



MICROORGANISMS 



constitute a well-defined scientific group of plants like those of 

 bacteria and yeasts. We are using this name for the group of 

 plants which we propose to study, because it is commonly ap- 

 plied to them by people who are not botanists and because 

 a more scientific classification 

 of them would lead us into 

 needless difficulties. 



A. B 



FIG. 264. Mold mucor. B shows a diagrammatic representation of 

 mucor, showing the profusely branching mycelium, and three vertical hyphse 

 (sporophares) , sporangia forming on 6 and c. 



MOLDS 

 436. Study of Molds. 



Exercise 85. I. Growing Molds 



Soak several pieces of bread in water until they become saturated, 

 and then place them in enclosed vessels of some kind where they will 

 remain moist. Set the vessels in a warm place and observe daily for 

 the growth of mold on the bread. When the mold first begins to 

 grow on the bread, it will appear as a soft, white, felty mass over 

 the surface of the bread or extending up from the surface resembling 

 a piece of very light gray fur. After a day or two, the mold will 

 begin to show some color. It may be pink, green, brown, black, 

 blue, or almost any color, depending on the kind of mold that you 

 chance to get. The plant body of the mold is always of the whitish- 

 gray color that appears first. The color, which appears later and 

 which helps us to distinguish the different kinds of mold is, in the 

 spores. 



n. Collecting Molds 



Search the garbage can at home, the fruit and vegetable cellar, 

 and the back yards of grocery stores for molds growing on decaying 

 fruits and vegetables. Almost any decaying object of this kind is 



