202 SPORE DISSEMINATION 



tinue to shed spores. Species of Lenzites, Daldalea, Schizophvl- 

 lum, Polvstictus, and Stereum, after having been dried for as long 

 as a year or two, may be revived in the presence of moisture, 

 \\ hereupon spore discharge is renewed. In the presence of vapors 

 of ether pr chloroform spore discharge ceases. Such reactions 

 leave no doubt that discharge is a vital phenomenon. 



The pilei of species of Coprinus are bell- or thimble-shaped. 

 Their srills undergo autodigrestion, commonly regarded as del- 

 iquescence. This process is a very important adaptation to insure 

 escape of the spores into the air, which is accomplished because 

 the spores on each gill mature and are discharged progressively 

 from the outer edge of the gill toward the stipe. Those portions 

 of the gills from which the spores have been shed are digested and 

 removed soon after discharge, and in consequence space is pro- 

 vided for the shedding of spores just above, as the pilei continue 

 to open outward like the opening of an umbrella. 



Spore discharge among Gastromycetes. The Gastromycetes 

 include a group of species whose best-known members are called 

 "purTballs" or "snuffboxes." The spore mass of the larger propor- 

 tion of species in this subclass is dry and powdery and therefore 

 admirably adapted for dissemination by air currents. The hygro- 

 scopic movement of capillitia aids in spore expulsion in certain 

 species. Some few are subterranean, and their spores are scat- 

 tered by rodents or burrowing animals that find the fruit bodies 

 attractive as food. Another group, the stinkhorns, possesses a 

 glebal or spore-bearing portion which is attractive to carrion 

 flies because of its putrid odor. These stinkhorns appear to de- 

 velop overnight, but actually the "eggs," encased in a protective 

 membrane or volva, have gradually been developing in the decay- 

 ing leaf mold. When the volva is ruptured, the spongy stalk or 

 receptacle, capped with the gleba, rather suddenly elongates in a 

 jack-in-the-box fashion. De Bary thought that this straightening 

 out or elongation of the stalk was caused by inflation from gas 

 within the tissues. Burt (1897) determined, however, that the 

 stretching is an osmotic phenomenon and that it occurs coincident 

 with the disappearance of a reserve of glycogen in and about the 

 receptacle, whose cells merely increased rapidly in size. 



These modifications in stinkhorns to insure spore dispersal are 

 much less spectacular and remarkable than those in Sphaerobolus. 

 Members of this genus occur on rotton wood and on the dung of 



