APPENDIX 269 



340° ( 1 70° C.) and kept at this temperature for one hour. After cool- 

 ing they are ready for use. In the following experiments it will be 

 understood that all glas.sware should be sterilized before using. 



Experiments illustrating the Molds 



1. Mold on Bread. Place several slices of bread under a bell glass 

 or any dish that will protect it from evaporation. Battery jars, large 

 beakers, or even common bowls will answer. Moisten the bread with 

 water and put aside in a warm place (80° to 95°). After two or three 

 days the bread will usually show signs of white mold. Allow the 

 mold to grow until some color appears and then determine, if possible, 

 whether there are more than one species of mold on the bread. 



2. Molds on Different Foods. Under separate bell glasses place 

 bits of cheese, some pieces of lemon, and a bit of banana. Each of 

 these should be moist. Cover and set aside as in the last experiment. 

 Molds will grow in a few days, but probably different species will grow 

 upon the different materials. Compare the molds and determine how 

 many kinds can be seen. 



3. Experiment to show the Mycelium. Place a little fruit juice, 

 such as may be obtained from canned fruit, in test tubes or in homeo- 

 pathic vials, and drop a few mold spores from the last experiment, or 

 a little dust from the floor, upon the surface of the liquid. Set aside 

 to grow, and notice how the molds spread and send fine threads into 

 the liquid. Later notice that colored masses of spores grow in the 

 air upon the surface but not in the liquid below. 



4. Spores. After the molds of the previous experiments have 

 begun to produce spores, as shown by the appearance of some color, 

 remove a little spore material from the surface with a knife blade or 

 a platinum wire and examine under a microscope. For this purpose 

 a compound microscope is necessary, since the spores are very small. 



5. Growth of Mold from Spores. Moisten a bit of bread and trans- 

 fer with a platinum wire a little bit of the spore mass from a vigor- 

 ously growing mold to the surface of the bread. Cover with a bell 

 glass and set aside for growth. Examine every day, and note that 

 molds start from the points where the bread was inoculated with the 

 mold spores. 



