THE SPHAEROBOLUS GUN 



283 



to the Plectobasidiales (Sclerodermales) than to the hymenium- 

 bearing Gastromycetes such as the Lycoperdales, but that to a 

 certain degree it occupies an intermediate position between the 

 two groups. However, Miss Walker found that, whereas in S. 

 stellatus true glebal chambers are never present and an orienta- 

 tion of the basidia is only to be seen in very young stages, 



Fig. 138. — Sphaerobolus iowensis. 

 A further stage in development 

 of the fruit-body. The glebal 

 chambers have increased in 

 size, and the various layers of 

 the peridium are distinguishable. 

 Section prepared and photo- 

 graphed by Leva B. Walker. 

 Magnification, about 40. 



Fig. 139. — Sphaerobolus iowensis. A further 

 stage in development of the fruit-body. 

 The glebal chambers lined by basidia have 

 now attained about their maximum size. 

 The various layers of the peridium are still 

 in course of development. Section pre- 

 pared and photographed by Leva B. 

 Walker. Magnification, about 40. 



in 8. iowensis true chambers are developed ' which persist up to 

 maturity and are very evident in dried unopened basidiocarps ' 

 and the basidia are arranged in definite hymenia, each hymenium 

 lining the cavity of a glebal chamber (Figs. 137-141). Hence, 

 while the absence of glebal chambers in S. stellatus would lead us 

 to place S. stellatus in the Plectobasidiales (Sclerodermales), the 

 presence of glebal chambers in 8. iowensis would lead us to place 

 8. iowensis near the Lycoperdales. But to separate S. stellatus and 

 8. iowensis, which on account of their numerous points of resemblance 

 are evidently but two species of a single genus, by placing them in 



