LEPIOTA CEPAESTIPES 19 



basidia always keep slightly in advance of the second, the second 

 slightly in advance of the third, and the third slightly in advance 

 of the fourth. The general result is that the four generations of 

 basidia produce their spores in a much shorter space of time than 

 would be taken if the method of development which we find in 

 fruit-bodies of the Panaeolus Sub-type were adopted. The spores 

 of the four generations reach maturity and are discharged in rapid 

 succession in correspondence with the times when they begin their 

 development. The following of one generation close behind another 

 in the maturing of their spores makes the brevity of the spore- 

 discharge period possible, and is evidently related to the ephemeral 

 existence of the expanded pileus. The production of four genera- 

 tions of basidia with differential protuberancy enables more spores 

 to be safely produced on, and discharged from, any given area of 

 the hymenium during the short spore-discharge period than would 

 be possible were the basidia all of equal length ; for, were they all 

 of equal length, they would require to be less crowded or there 

 would be jostling of the spores borne on adjacent basidia. The 

 differential basidial protuberancy is therefore an economical arrange- 

 ment : with it many more spores can be produced by the fruit- 

 body than would be possible without it. We have thus been able 

 to connect the polymorphism of the basidia with the general re- 

 quirements of the fruit-body as an ephemeral organ. One other 

 fact requires to be explained, namely, the large size of the paraphyses 

 as compared with those of the Panaeolus Sub-type. The para- 

 physes in Lepiota cepaestipes have two functions : (1) they help to 

 support the basidia in a vertical position, so that the spores are 

 freely developed and subsequently discharged into the interlamellar 

 spaces, and (2) they act as space-making agents, i.e. they separate 

 the basidia and keep them at such distances apart that the spores 

 of adjacent basidia develop without any mutual interference. If 

 one were to take away the paraphyses in Fig. 7, C (p. 14), and set 

 the basidia in contact, there would result such a crowding of the 

 basidia that few spores could be properly developed and discharged. 

 Even if the diameters of the paraphyses were reduced to one-half, 

 the beautiful freedom of each separate basidium would be seriously 

 hampered. It is evident that the paraphyses are structures which 



