320 



DIVISION II. COURSE OF DEVELOPMENT OF FUXGT. 



towards the upper end, where the margin at length reaches nearly to the apical surface 

 of the peridium (Fig. l$o A). By the formation of this gelatinous layer the dense 

 non-gelatinous tissue outside it is separated from the rest and becomes the lateral 

 wall of the peridium, which is then differentiated into two concentric layers, an outer 

 permanent layer of brown felt and an inner whitish layer. Meanwhile no separ- 

 ation takes place in the middle and beneath the apex, but the dense still undiffer- 

 entiated primitive tissue extends from the latter into the interior space as a thick round 

 sac. At length the differentiation spreads further into the interior of the originally 

 uniform mass, while all the parts increase simultaneously in volume. Portions 



which are at first round in form become 

 more dense and are separated from one 

 another by the spread of the gelatinisation 

 from without inwards successively between 

 them (Figs. 150.5, 151). These are the 

 primordia of the chambers of the gleba 

 or peridiola. During their further inde- 

 pendent growth, the gelatinisation goes 

 on also beneath the apical surface, which 

 is now covered only by a thin continua- 

 tion of the inner wall of the peridium. 

 The apex is at first clothed with brown 

 hairs ; as it increases in size with the 

 general growth the hairs are pushed aside 

 and no new ones are formed ; the summit 

 is therefore destitute of the covering of 

 hairs, and is a thin white membrane, the 

 epiphragm (Fig. 150 D], which becomes 

 torn up and disappears at maturity, The 

 gelatinous tissue round the peridiola also 

 disappears, and the latter lie heaped up 

 at the bottom of the now open cup-shaped 

 sporophore. 



The peridiola grow from their first be- 

 ginnings into a lenticular form, and be- 

 come inclined obliquely at an acute angle 

 opening upwards to the lateral wall of the 

 peridium (Figs. 150 C, 152). A central 

 cavity appears in them at an early period, 

 filled at first, it is said, by a felted gela- 

 tinous tissue which afterwards disappears, 

 but this perhaps is uncertain ; the cavity 

 has the same shape as the peridiolum, and 

 continues relatively small, and is densely 

 filled at the time of maturity with some- 

 what long spores. Two to four spores are 

 formed on each of the basidia, which, with 



the paraphyses, form a dense hymenial layer lining the cavity. The constituents of 

 the hymenial layer become thick-walled after they have produced the spores and form 

 a stout palisade layer round the cavity, and this is again invested by the still harder 

 thick outer wall of the peridiole, into the structure of which we must not enter further 

 in this place. 



From the accounts which we possess it seems certain that the course of the develop- 

 ment of the compound sporophore is similar in the genera Cyathus and Nidularia 

 to that here described in the case of Crucibulum, the only exception being that in 



FIG. 152. Crucibulum vulgarc. Thin median section through 

 a sporophore like that in Fig. 151, more highly magnified. Two peri- 

 diola with their funiculi are cut through the middle ; a third tying 

 between them is cut through on the outside only. Meaning of the 

 letters as in Fig. 15:. After Sachs. 



