i 9 2o] WALKER— CYATHUS l< 







a half years. The writer's cultures were never maintained for so 

 long a period. 



Origin of basidiocarp. —The basidiocarps arose from mycelial 

 strands or from densely interwoven vegetative mats of hyphae. 

 Not uncommonly young fruit bodies developed on the inside of 

 old peridia which had lost their peridioles. The youngest basidio- 

 carps obtained were about 0.5 mm. in height and showed no 

 internal differentiation, except that the mass took the stain 

 slightly more deeply at the top where the filaments were much 

 smaller (about 1 . 5 m in diameter) and more closely interwoven 

 than at the base. Figs. 49-52 show some of these young basidio- 

 carps, while fig. 65 is a higher magnification of the upper portion 

 of the fruit body shown in fig. 50. At the base of the knot the 

 filaments are larger (about 2.5-3 /x in diameter), where they 

 spring from a mycelial strand or mat, and branch at first in a fan- 

 like manner, soon becoming much branched and interwoven as they 

 ascend, and gradually passing into the smaller filaments at the top. 

 In the region made up of these small, closely interwoven filaments 

 many large intermycelial spaces are present (fig. 65). Even these 

 youngest fruit bodies are covered densely with yellow, much 

 branched, thick- walled hairs with toothlike projections (fig. 65). 

 These hairs are 3 . 5-4 ju in diameter, and so conspicuous that the 

 smallest basidiocarps found could be distinguished only by the 

 presence of yellow tufts made up of these hairs. 



Internal differentiation of basidiocarps. — The first dif- 

 ferentiation here, as in Cyathus fascicular is, consists in the gelatini- 

 zation of filaments. This zone is very vague in its early stages, 

 and it is difficult to be certain just when it begins. Filaments 

 just beginning to gelatinize seem to take the stain more deeply 

 than ungelatini/ing filaments, and soon to lose this power and take 

 the stain less deeply. Using these properties and a very slight 

 difference in appearance as determining factors, it seems that 

 the gelatinization begins at the base of the fruit body (fig. 52) and 

 progresses upward in an annular fashion (fig. 53), the darker regions 

 on the sides representing the region just beginning to gelatinize, 

 and the lighter region below representing the more gelatinized 

 filaments. Sachs (8), in his description of the development of 





