72 A MONOGRAPH OF THE GENUS PODAXIS DESV. (= P0DAXON FK.). 



ment of the very varied and complicated structures presented by the 

 different sections, it is difficult to realize that the only known idea 

 embodied is, as already stated, a determination on the part of every 

 generic assemblage to outvie its neighbours in providing the most 

 perfect arrangement for securing the world-wide distribution of its 

 own kind. 



Accepting tbe genera Podaxls and Tulostoma as at present 

 defined, we find the gradual transition from the ascosporous to the 

 basidiosporous type effected as follows. In Podaxis it has been 

 shown that the asci generally originate in a crowded manner from 

 special, short, variously-branched, closely-septate hyphse, but in 

 most species we find along with this typical method certain asco- 

 genous hyphse sparingly or not at all branched, and with fewer 

 septa ; now in P. Emeriti the last-mentioned exceptional form of 

 ascogenous hyphse is found to be typical ; furthermore, the ex- 

 ceptional mode of spore-formation in most species, where the ascus 

 remains as an outer coat to the spore, is also the rule in P. Emeriti. 



The peculiar nature of the basidia in the genus Tulostoma was 

 first described by Schroter,* who shows that in T. mammozum these 

 structures originate as short lateral branches from the hyphse of the 

 spongy gleba. These short lateral branches, after receiving the 

 protoplasm from the parent hypha, are cut off from the latter by a 

 septum near the base ; the terminal portion increases in diameter, 

 but remains more or less cylindrical, and is now a basidium, as 

 proved by the appearance of four lateral papillae, which continue to 

 increase in size, absorb all the protoplasm from the basidium, 

 become cut off from the latter by a septum at the neck, and finally 

 drop off as spores. Schroter has given five figures of the basidia,! 

 each bearing four spores showing the scattered and generally lateral 

 mode of origin ; in one example there is a terminal spore, but there 

 is evidently no stereotyped definite position as shown in typical 

 basidiomycetes. 



In a young specimen of Tulostoma pitsillum Berk. I find the same 

 thick, cylindrical, aseptate basidia bearing from six to eight lateral 

 spores, and in Corda's figure of Tulostoma fimbriatitm the spores are 

 represented as originating in elongated clusters, suggesting the idea 

 of a lengthened basidium covered with numerous spores ; this I 

 have had no opportunity of corroborating, nevertheless we see that 

 in the species of Tulostoma the basidia originate as lateral branches, 

 and produce lateral spores, irregularly arranged, and variable in 

 number, thus presenting many points in common with the homo- 

 logous parts in Podaxis, in fact only differing in the total absenc 

 of septa in the basidium, and in the wall of the basidium becoming 

 the wall of the spore. 



Podaxis Emeriti is the existing connecting-link between the 

 extremes of structure met with hi Podaxis and Tulostoma respectively. 

 In an immature specimen of Batartea Steveni I have succeeded in 

 ascertaining that the asci are clavate, and at the apex of the basidia 



* Entw. u. Tulostoma, in Cohn's Beitr. ii. p. 

 t Tom. cit. p. 68 (woodcut). 



