220 DIVISION II. COURSE OF DEVELOPMENT OF FUNGI. 



as a large-celled envelope. The round coil then developes into the at first cylin- 

 drical sporocarp by the aid of branches from the primordium and from its envelope, 

 which have the same relation therefore to each other in this respect as the primordium 

 and medulla in S. Sclerotiorum. The incipient sporocarp is therefore now seated 

 on the rind of the sclerotium in the same form as the one represented in Fig. 105 

 beneath it. Meanwhile more branches from the elements of the medulla have 

 grown through the rind up to the envelope, so that the rind is pierced by a 

 strand of hyphae as broad as the sporocarp and passing into the envelope, a 

 condition of things which continues in the form represented in Fig. 19. What- 

 ever could be observed of the final maturing of the sporocarp is the same as in 

 S. Sclerotiorum. 



13. According to Gibelli's and Griffini's researches confirmed by Bauke the 

 development of the perithecium in Pleospora herbarum differs to some extent from 

 those described above, the perithecium being formed by differentiation at a late period 

 of growth of a spherical primordium originally composed of a uniform pseudo- 

 parenchyma. This arises from one or two adjacent mycelial cells which are converted 

 into the spherical primordium by active cell-division in every direction. The 

 initial cell was previously constituted by one, rarely several, hyphal branches, which 

 show no fixed arrangement and no peculiar changes in their further development. 

 Then a bundle of slender paraphyses springs from the basal region into the parenchy- 

 matous body, displacing and dissolving its original central tissue, and grows on into 

 the inner space ; and after that, in the observed cases after a winter's rest, the asci 

 are formed ' in the middle of the paraphyses as branches from their basal cells ; ' the 

 paraphyses swell into a jelly and disappear as the asci mature. 



Similar proceedings are perhaps to be observed in Sphaerella Plantaginis ac- 

 cording to Sollman's statements 1 , but these are not to be relied upon. 



14. In Claviceps purpurea, according to Fisch, the formation of the perithecia 

 begins with the differentiation of a few cells in the periphery of the young capitate end 

 of the stroma which proceeds from the sclerotium (see page 38 and also section LXV). 

 Two or three hyphal cells become filled with strongly refractive protoplasm and 

 begin to form by divisions in all directions a very small roundish or elongate-ellipsoid 

 cellular body, which is clearly distinguished from the pseudo-parenchyma of the 

 capitulum by the small size of its cells and the nature of their contents. The mode 

 of formation of the cavity of the perithecium could not be certainly ascertained ; but 

 in all probability it is effected by the mutual separation of the cells in the interior, 

 either by the simple parting of the walls or by dissolution of a cell-layer ; in this way 

 a cavity would be formed, the roof of which would be the greater portion of the wall 

 of the perithecium, and its floor become the incipient hymenium. The young peri- 

 thecium as a whole soon acquires the form of an elongated cone by growth in the direc- 

 tion of the radius of the capitulum, and this change is accompanied by an elongation 

 of the whole peripheral cell-layers of the body, thus plainly delimiting the wall of the 

 perithecium. The point of the young perithecium elongates above into a cone, and 

 forms a canal which is beset all round from below upwards with periphyses, while small 

 protuberances grow out of the upper cell-layers of the young hymenium and lengthen 



1 Bot. Ztg. 1864, p. 281. 



