286 



The North American Cup-Fungi 



apothecia to dehisce. In this case they split into several Geaster- 

 like rays, hence the name. These roll back so that the hynienium 

 is freely exposed at maturity-. In a previous paper the writer 

 has called attention to the peculiar bladder-like swelling of the 

 cells of the paraphyses which seems to be a device for expanding 

 the hymenium in order to facilitate the discharge of the spores 

 (Plate 60). This has not been observed in any other species. 

 On the question of spore discharge K. B. Boedijn (see bibli- 

 ography) seems to differ with the writer. The difference is, 



Fig. 16. Photograph of spore discharge in an operculate discomycete, 

 Unnila Geaster. Photo by G. W. Goldsmith. 



however, apparently due to misunderstanding rather than to con- 

 flicting observations. The writer claimed (p. 20) that since the 

 ascostome is much narrower than the spore which has passed 

 through it, the ascostome must have stretched and contracted 

 as the spore passed through, and that this expansion and con- 

 traction tends to accelerate the force with which the spore is 

 ejected or "snapped out" of the ascus. 



In answer to this Boedijn states: "A contraction between 

 each spore ejection, as suggested by Seaver (p. 21), does never 



