40 NATURE STUDY. 



begin by gathering the different forms that may be found and 

 determining where the spore bearing surface is in each. As has 

 already been seen in Fig. 14, the spore bearing surface of the com- 

 mon edible mushroom is on the gills on the under side of the cap. 

 There are many forms like this from which spore prints can be 

 obtained. 



Another large group of mushrooms bears the spores on 

 the surface of small tubes which are in the part under the 

 cap, or under the shelving masses growing on the sides of 

 stumps or logs. Fig. 16 is a very common form found in lawns, 

 in the woods under pine trees and in other situations. It is 

 known as Boletus and there are many species of this genus: The 

 illustration shows the tubes on the under surface of the cap. 



Fig. 17 repiesents a spore print of this Boletus, taken by 

 cutting off the cap and placing it bottom side down on a sheet of 

 paper and allowing it to remain for some hours when it dis- 

 charges its spores down the 

 tubes thus outlining the un- 

 derside of the fungus. 



The puff-balls keep their 

 spore surfaces inclosed in 

 a sac, while the spores 

 are forming. When they 

 are ripened the sac be- 

 comes dry and breaks open 

 at the top. Any slight 

 shake on it sends out a 

 puff of smoke. The smoke 

 is a cloud of spores. 

 Fig. 17— Spore print of tht Boletus of Figr. 16. Some of the puff- balls in 

 California grow to the enormus size ot a foot in diameter. 

 These when growing, while still white are excellent food, many 

 thousands of pounds of which go to waste every year. 



