212 



INTRODUCTION TO THE STUDY OF FUNGI 



Fig. 100. — Stroma and peri- 

 thecia of Mdanconis. 



Melanconium. In some of the species the ascigerous perithecia 

 have been found growing in the midst of the pustules of 

 conidia, and in others closely associated in contiguous pustules. 

 In another genus, that of Pseudovalsa, 

 the sporidia are septate and coloured, 

 but there is no Melanconium to which 

 the species are related. When the 

 sporidia are uniseptate they fall into 

 the subgenus Valsaria, but when three 

 or more septate into the subgenus 

 Aglaospora. Only one other genus of 

 the Valseae remains to be alluded to, 

 and that is Fenestella, in which the 

 sporidia are multiseptate, and divided 

 in both directions so as to be muriform 

 or clathrate. It may be intimated that of the species of 

 genuine Valsa, with sausage-shaped sporidia, very many of 

 the species -are genetically connected with species of Cyto- 

 spora, a genus of Sphaeropsideae, in which the spores are also 

 sausage-shaped and hyaline, but without asci, being Nproduced 

 on short slender threads within a kind of spurious compound 

 receptacle which greatly resembles Valsa in appearance. 

 These conidia are often found growing on the same twigs as 

 Valsa, or upon twigs upon which the Valsa appears sub- 

 sequently, but the precise influence of the one upon the other 

 has not yet been demonstrated. Other species of the Valseae 

 have been named in conjunction with species of other genera 

 of Sphaeropsideae, but less universally. In like manner species 

 of Pseudovalsa are related to the similar, but stylosporous, fructi- 

 fication of species of Coryneum. 



The last subfamily is Eutypeae, and here the leading 

 feature, as distinct from Valseae, is that the stroma is broadly 

 and indefinitely effused, beiDg formed from the more or less 

 changed matrix. The perithecia are immersed in the stroma, 

 and for the most part are densely and broadly gregarious. 

 Eutypa is the typical genus, often occurring on naked wood, 

 the substance of which is transformed into a stroma, in which 

 the perithecia are immersed. In about half the species the 

 ostiola are sulcate, and in the other half they are not. The 



