434 RESEARCHES ON FUNGI 



three hymenial waves by describing the basidia of the fore part of 

 the third wave. No. 60 is almost, if not quite, of full length. 

 No. 55 has "certainly not attained its full length and is therefore 

 not yet fully protuberant. Nos. 46, 42, and 34 are progressively 

 younger and less protuberant. No. 31 which forms the foremost 

 element hi the wave is simply a future-generation basidium, which 

 does not yet protrude beyond the general level of the hymenium. 



The subhymenium $ consists of some three or four layers of 

 rounded or oval cells. There is no sharp and level plane separating 

 the hymenium from the subhymenium, such as many writers have 

 imagined. Some of the basidia, namely, the oldest (the earliest 

 to develop spores), arise very deeply in the subhymenium, either 

 toward its middle or sometimes even lower. In Fig. 147 (p. 429), 

 the most striking basidia, so far as depth of origin is concerned, 

 are nos. 30 and 51, but nos. 5, 11, 13, and 38 are also noteworthy 

 in this respect. The basidia which successively come to maturity 

 during the several days of the spore-discharge period arise more 

 and more toward the top of the subhymenium. The paraphyses 

 are situated quite superficially : the small subhymenial cells from 

 which so many of them arise appear to be almost pedicellar in 

 their nature (cf. the cells beneath the paraphyses nos. 1, 4, 10, 25, 

 26, 33, etc.). 



The trama t consists of large elongated cells attached together 

 in chains which are irregularly anastomosing and which tend to 

 run in a direction parallel to the median line of a cross-section of 

 the gill. Sometimes there are a few narrow elongated hyphae just 

 beneath the subhymenium where the trama begins. Some have 

 been represented in Fig. 147. 



At the stage of development shown in Fig. 147 (p. 429), the 

 hymenium contains a great deal of protoplasm and accumulated 

 food-stuffs. Cell-contents are particularly heavy in the younger 

 present-generation basidia, in the coming-generation and in the 

 future-generations basidia. There is a less amount of protoplasm 

 in the paraphyses. On account of the presence of heavy cell- 

 contents, the hymenium appears very dense even in thin sections, 

 which fact constitutes one of the difficulties in making out the 

 cell-outlines. The subhymenium also contains a large quantity of 



