4O DIVISION I. GENERAL MORPHOLOGY. 



instead of forming new rind. The sclerotia of the Typhulae in which the tissues are 

 very distinctly differentiated appear not to be capable of these acts of regeneration. 



The following remarks are intended to illustrate and complete what has been stated 

 above. 



The production of the primordia of sporophores from the cells of the rind of 

 Coprinus stercorarius is given on the authority of Brefeld. It is not strange in 

 itself, even in presence of the facts illustrated in Figs. 18 and 19, that the superficial 

 cells of the sclerotium should remain capable of further development and of branching, 

 and that the ordinary distinct division of labour between the protecting rind and 

 the medulla should in some cases not be observed. There is therefore no antecedent 

 difficulty in admitting a third mode of production such as Brefeld gives in the case 

 of Sclerotinia Sclerotiorum, in which the medullary cells and cells of the rind both par- 

 ticipate. But I have not admitted this case into my account because the facts will not 

 bear this interpretation. Young shoots always spring in this species from the medulla 

 in the peculiar manner which will be described in Division II, and burst through 

 the rind to reach the surface. In somewhat older specimens, such as those which 

 are very beautifully and correctly portrayed in Brefeld's Table viii. Fig. 9, the true 

 state of the case is obscured by the circumstance that the superficial cells of the 

 sporophore from the point of emergence are very like those of the rind of the 

 sclerotium in shape and in their dark colour, so that the new cells appear to be 

 directly continued into the superficial cells. Thin sections even in more advanced 

 states of growth under sufficient magnifying power show that the case is as I have 

 stated it, and exhibit clearly the arrangement of the black superficial cells, which 

 are the extremities of hyphal branches proceeding from branches of the emerging 

 tuft of hyphae and passing to the surface in diverging curved directions. 



That the shoots from the sclerotia in the cases described above should always 

 have been termed primordia of sporophores requires no special explanation, even in 

 the case of Sclerotinia Sclerotiorum where they may under unfavourable circumstances 

 develope in the ground into long branched strands. Even the normal sporophores 

 of this Peziza may be branched, and the branches of the strands may under favour- 

 able conditions of development revert to the normal sporiferous state. Brefeld indeed 

 saw them on several occasions produce a filamentous mycelium which subsequently 

 formed sclerotia ; but these are monstrous developments such as occur also elsewhere, 

 the exceptional cases that confirm the rule. 



It is true that phenomena have been reported in connection with the formation 

 of shoots from sclerotia, which vary from the descriptions in the text ; but more 

 searching investigation is needed in all these cases. Thus Tulasne saw sclerotia 

 of Hypochnus centrifugus, which had been placed in damp sand in the end of April, 

 produce in August and September a filamentous mycelium like a spider's web, which 

 subsequently developed the ordinary sporophores of Hypochnus. As regards the 

 connection of the mycelial hyphae with the sclerotium it is merely stated that they 

 spread in every direction from its surface. The consistence and structure of the 

 sclerotia remained unchanged after the production of shoots ; hence Tulasne rightly 

 considers our knowledge of them as not yet complete. 



Tulasne has already pointed out that Leveille's older statement, that a floccose 

 mycelium is first produced from the sclerotia of Agaricus grossus, A. stercorarius, 

 A. racemosus, and A. tuberosus, and afterwards sporophores from the mycelium, is 

 founded on a mistake. 



Another exceptional occurrence, demanding more critical investigation, is described 

 by Micheli 1 as taking place in Peziza Tuba, Batsch, a species which seems scarcely 

 to have been examined since his time. The sclerotium as it lies in the ground puts 



Nova plantarum genera (1729), p. 205. ' Fungoides. No. 5.' 



