2l8 DIVISION IT.— COURSE OF DEVELOPMENT OF FUNGI. 



refringent plates like those of the trichogyne of Collema ; but at length they entirely 

 disappear, the last remains being still recognisable as the paraphyses begin to form. 



From Fiiisting's 1 many researches it is more than probable that the development 

 of the perithecia inside the stroma, not only in all the species of Xylaria and in 

 Ustulina where I observed it some time ago, but also in the genera Diatrype, 

 Stictosphaeria, Futypa, Nummularia, Quaternaria, and Hypoxylon, runs essentially the 

 same course as has now been described in Xylaria polymorpha, with the exception of 

 course of specific differences of shape and especially of the formation of the wall and 

 the orifice. In all cases there appears, especially in the delicate coil of hyphae which 

 forms the primordium, the row of broad cells irregularly rolled up and full of 

 protoplasm, which Fiiisting terms Worotiin's hypha ; in all cases Fiiisting observed 

 the gradual disappearance of these cells without being able to prove a direct connection 

 between them and the ascogenous hyphae, which sprang finally with the paraphyses from 

 the wall of the perithecium in similar relations to them of place and time as in Xylaria. 

 It is true that the views and objects of observers have so far changed since his in- 

 vestigations that his statements cannot be regarded as certainly infallible, and fresh 

 examination might not be superfluous. 



12. The sporocarps of Sclerotinia Sclerotiorum, the conformation of which 

 was shortly described on page 52 (see Fig. 106), show, as the cup begins to 

 expand, the first asci between previously formed paraphyses, and new paraphyses 

 are added one after another with the growth of the margin of the cup, and then more 

 asci are interposed between them, at first singly, but afterwards in greater num- 

 bers and crowd out the paraphyses. Asci and paraphyses are of course branches 

 or the extremities of branches of the hyphae of which the original bundle was com- 

 posed ; but the asci when once found cannot be referred back with the paraphyses to 

 common parent hyphae ; only hyphae are found, as Brefeld also states 2 , which terminate 

 either in paraphyses or in numerous asci ; the latter hyphae penetrate deep into the 

 subhymenial layer. In this layer the ascogenous hyphae cannot be distinguished from 

 the others, and where their first origin is to be found, remains uncertain. The examina- 

 tion of the first beginning of the cup in the sclerotium leads to a conjecture on the 

 subject. Certain bodies are formed in sclerotia, if kept moist, before there is any 

 external appearance of sporocarps. These bodies, which here too may be termed 

 primordia (Fig. 104), appear in large numbers in the periphery of the sclero- 

 tium, either close beneath the black rind or a little further in, as round trans- 

 parent objects about 70-100 m in diameter. They consist of a coil of very narrow 

 tangled hyphal branches with gelatinous membranes ; their cavities, which are filled 

 with protoplasm, appear to run through a homogeneous jelly. They originate in 

 single stout medullary hyphae of the sclerotium which are not distinguished from the 

 rest in any other way ; branches from these hyphae form the coil of filaments, and its 

 development is accompanied with displacement and gelatinous disorganisation of the 

 adjacent medullary hyphae. The bundle of hyphae of which a cup is formed always 

 bursts from the sclerotium above a primordium of this kind (Fig. 105), and consists of 

 a smaller central portion which branches off directly from the primordium, and a larger 



Bot. Ztg. 1867. ' Schimmelpilze, IV. 



