332 A TEXTBOOK OF THEORETICAL BOTANY 



ends. Some of these cells are at first binucleate, but when the peridioles are 

 mature the nuclei of these cells fuse to form the primary nuclei of basidia, 

 which are thus separated from one another by uninucleated paraphyses. 

 From these basidia the basidiospores are abstricted into the central cavity 

 of the peridiole, which in this way become filled with basidiospores which 

 are said to be binucleate. 



During the internal development of the peridiole its external tissue 

 becomes difi^erentiated into a thin, colourless, easily removable coat covering 

 a pseudoparenchymatous inner layer, so that at maturity a number of 

 separate layers can be made out between the hymenial surface and the outer 

 surface of the peridiole. 



In Cyathiis stn'atus, as in other members of the genus, the peridioles are 

 attached to the endoperidium by means of a short cord or funiculus (Fig. 

 327). This consists of a spirally twisted mass of longitudinally running 



EPIPHRAGM 



EXOPERIDIUM 



ENDOPERIDIUM 



PERIDIOLUM 



CULUS 



EXOPERIDIUM 



EAD 



ENDOPERI 



Fig. 327. — Cyathus striatus. A, Vertical section through two fruiting bodies showing 

 on the left the young closed state, and on the right the fruit opened and the 

 epiphragm ruptured. B, A peridiolum. C, Section showing the coiled thread 

 in the stalk of the peridiolum and its attachment to the endoperidium. {After 

 W. Smith.) 



