1 8 BOTAXTCAL GAZETTE [july 



Development of peridium and epiphragm.— The mature pe- 



ridium (fig. 63) would closely resemble that of Cyathus fascicularis 

 andC. striatusii the middle pseudoparenchymatic layer were omitted. 

 The outer layer consists of loosely interwoven, largely longitudinal 

 filaments giving rise to long flexuous hairs on the outside. Among 

 these hairs can be seen only rarely, more often toward the top, 

 traces of the much branched, sharp pointed hairs that originally 

 covered the entire fruit body. The filaments comprising the outer 

 part are thick-walled and brownish, becoming thinner- walled and 

 colorless toward the inner portion, and thus merging into the 

 inner layer, which is composed of more or less gelatinized filaments. 

 This peridium covers the sides and converges slightly over the top 

 of unopened fruit bodies (fig. 61). 



These zones of the peridium are quite well differentiated before 

 the primordia of the peridioles appear, and the outer zone under- 

 goes little change during subsequent development. On the other 

 hand, the inner zone changes greatly. In the young fruit bodies 

 (figs. 55, 56) it is a wide zone, but as the glebal region develops it 

 becomes more and more compressed (figs. 57, 59), until in the 

 mature basidiocarp it forms an almost indistinguishable layer 

 (figs. 61, 70). 



The epiphragm covers the upper surface of the fruit body and 

 is definitely marked by the time the basidiocarp is half developed 

 (%• 58)- It consists of the entirely undifferentiated upper part 

 of the basidiocarp as seen in younger stages (figs. 55, 56), and is 

 as densely covered by the much branched, pointed hairs as was 

 the original young fruit body (figs. 49-54). Following the gelatini- 

 zation of the filaments surrounding the peridioles, those con- 

 stituting the epiphragm also undergo gelatinization. The epiphragm 

 just before gelatinization is shown in fig. 62. There is no opening 

 up of the upper portion by the spreading of the superficial layer as 

 described for C. fascicularis. 



Comparisons 



From Fries's description of the development of Nidularia it 

 evidently has the simplest structure of any of the Nidulariaceae 

 whose development has been studied. Its development seems to 

 correspond very closely with that of Crucibulum, except that the 



