Rural School Leaflet. ^y^ 



fiumters of tiny, black specks attached to the mycelium threads — the 

 spore cases, each one called a sporangium (a cheap hand lens with each 

 culture will help the children to see these better). Some of the sporangia 

 are white. Note that they grow in clusters, at the ends of long mycelium 

 threads like strawberry plants at the ends of runners. These are young, 

 unripe ones. Moisten the end of the finger and draw it gently over the 

 ripe sporangia. Observe the dark dust that clings to the finger. This 

 is made up of great numbers of the spores. These are produced inside 

 the sporangium (Fig. la.) whose thin walls were broken by your finger. 

 These spores are too small to be seen separately with your naked eye or 

 even the hand lens (see Fig. ib). These spores correspond to the seed 

 in the bean pod. The sporangiwn corresponds to the bean pod itself. 

 When the spores fall on moist places they sprout or germinate as shown 

 in Fig ic. If the right kind of food be present the sprout or germ tube, 

 as it is called, grows, branches, and develops into the mycelium which 

 was studied in the first lesson. Compare with the checks. What 

 effect does heat, moisture, and light have on spore production? 

 Suggestions for Study. 



1st. To show the light relations of this fungus. — Make a cover of black 

 paper that will just slip down over the tumbler. Cut a slit half an inch 

 wide and an inch long in one side of the cover. When the culture begins 

 to show sporangia, slip the cover over the tumbler and set with the slit 

 toward the light. Remove cover and examine in a day or two. Why 

 does the mold grow toward the light? Note that it is chiefly the spor- 

 angia stalks that reach toward the light. 



2nd. To show the air relation.^ — When the mold shows good growth, 

 lift one edge of the tumbler by inserting under it a match or splinter. 

 The threads grow toward this opening. Why? What is in the air that 

 they need? Plants breathe oxygen the same as animals do. Place a 

 small dish of lime water under one of the tumblers. It is soon coated 

 with a film of lime. The fungus gives off Carbon Dioxide just as animals 

 do when they breathe. 



Notes. — Contaminations . — Other molds and bacteria will frequently 

 get into the cultures. They can be told from the bread mold by the 

 different color and character of their growth. They are like weeds — 

 plants out of place. 



Hand lenses are not necessary, but they help the children to see the 

 parts better. Cheap magnifying glasses, which will answer the purpose 

 admirably, ma}^ be purchased of any optical company. Bausch and 

 Lomb Optical Co., Rochester, or Spencer Lens Co., Buffalo, will send 

 catalogues. 



