

1 9 20] WA LKER—CYA TH US 1 1 



body (figs. 17, 22) the middle or pseudoparenchymatic layer ter- 

 minates, and the peridium over the top is composed of the fila- 

 ments from the outer zone, which here give rise to especially long 

 hairs, and of imgelatinized portions of the inner zone of the peridium. 



As the fruit body matures lateral expansion takes place. 

 This causes a rupture in this upper region, the parts structurally 

 connected with the peridium being pulled off from over the top, 

 leaving exposed the little differentiated ground tissue below 

 (figs. 7, 8), which appears as a smooth uniform covering. Text 

 fig. 3E-H illustrates how this takes place. A young basidiocarp 

 of about the same age as the one shown in fig. 1 7 was marked with 

 India ink as illustrated in E and F y while G and H show the con- 

 dition a few days later. 



Since the gelatinization of the ground tissue of the gleba begins 

 at the base and progresses upward, the tissue at the top is the 

 last to undergo gelatinization. This, together with the drying 

 effect of the air, results in the formation of a thin membrane, 

 the epiphragm, covering the top, which is exposed by the breaking 

 away of the earlier covering parts. The epiphragm finally ruptures 

 (fig. 5) and itself undergoes gelatinization, leaving the fruit body 

 entirely open on the top. The moisture resulting from gelatiniza- 

 tion dries out, and the peridioles sink to the bottom. Thus the 

 basidiocarp assumes its characteristic mature appearance. 





Cyathus striatus Willd. 



My studies of this species, based largely upon a small collection 

 of only about 20 basidiocarps made during July 1913 on the campus 

 of the University of Wisconsin at Madison, are necessarily quite 

 incomplete. While this species is quite common in all regions 

 where the writer has collected, it has been impossible to get young 

 stages in most cases. It is included here because it displays some 

 variations in development from that of C. fascicularis, and because 

 of the close agreement with Tulasne's (9) work upon this species, 

 and because Tulasne shows its close resemblance structurally 

 to C. fascicularis. 



The material was fixed in Flemming's medium and weak solu- 

 tions, dehydrated, cleared in xylol, and sectioned in paraffin. 





