284 



RESEARCHES ON FUNGI 



different orders would be taxonomically absurd. It is therefore 

 best to keep the two species together and to accept Miss Walker's 

 conclusion that the presence or absence of glebal chambers is not 

 a good criterion for distinguishing between these orders of the 

 Gastromy cet es . * 



The Species of Sphaerobolus. — Fischer, 2 in 1900, stated that there 



were five species of 



^ 







#• 



■ 



Sphaerobolus but 

 that only S. stellatus 

 Tode was known in 

 detail. Rea,inl922, 

 in his British Basi- 

 diomycetae enumer- 

 ates three species : 

 iS. stellatus Tode, S. 

 dentatus (With.) 

 W. G. Sm., and S. 

 terrestris (A. et S., 

 non Tode) W. G. Sm., 

 but it is uncertain 

 whether or not S. 

 dentatus and S. 

 terrestris are really 

 distinct from S. 

 stellatus. 



A critical com- 

 parative study of 

 four North- American 

 strains of Sphaero- 

 bolus has been made by Miss Walker. 3 She grew all the four 

 strains in pure cultures and found that two of them were typical 

 S. stellatus, that one of them was a new variety of S. stellatus which 

 she named S. stellatus var. giganteus, and that another of them was 

 an entirely new species which she named S. iowensis. The un- 





'^g^e 





[Fig. 140. — Sphaerobolus iowensis. A further stage in 

 development of the fruit-body. The glebal 

 chambers are becoming filled with spores and 

 thus obliterated. Toward the top, in the still 

 open chambers, the spores are still adhering to 

 their basidia. Section prepared and photo- 

 graphed by Leva B. Walker. Magnification, 

 about 40. 



1 Leva B. Walker, ibid., pp. 174-175. 



2 E. Fischer, in Die nat. Pflanzenfamilien, loc. cit., p. 346. 



3 Leva B. Walker, loc. cit., pp. 151-172, Plates XVI-XXV. 



