Minnesota Plant Diseases. 



i»i 



exceedingly poisonous and fungus eaters must take good care 

 that they are familiar with the poisonous varieties found in the 

 state. (Figs. Frontispiece, 6 to 8, lo, i8, 20, 81, 86 to 89, 116, 

 128 to 132.) 



Puff-balls and their allies (G aster amy cetes). All of the re- 

 maining basidium-bearing fungi have closed fruiting bodies. 

 The basidia are borne inside of this structure either in palisades 

 lining the surface of chambers or in irregular fashion on loose 

 threads throughout the fruiting body. The latter arrangement 



Fig. 90. — A group of the common gemmed puff-balls (Lycoperdon gemmatum) just before 

 opening; the position of the future opening is seen at the darkened tops of the 

 fruiting bodies. Original. 



is prevalent in the wefted puff-balls (including the first, second 

 and third of the following groups), while the remaining groups 

 possess the palisade arrangement of basidia. The fruiting body 

 always possesses one or more covering membranes. These 

 fruiting bodies may remain closed until the membranes de- 

 cay, when the spores are released, or they may open in charac- 

 teristic ways, by pores or by splitting, and thus allow of the es- 

 cape of the spores. In most forms the interior of the fruiting 

 body partially disintegrates, leaving only the spores in a fine dust 

 held in a loose weft of long and strong threads which give the in- 

 terior a sponge-like texture. The spores are then thrown out in 



