378 FUNGI 



Ascomycetes, Eremascus, Pyronema, and Ascobolus. In most cases, 

 however, there intervenes the formation of non-sexual spores which may 

 be in a species all of one sort, e.g., Erysiphe, Peronospora ; or of several 

 sorts ; and such spores are, moreover, in many cases exceedingly alike. 

 Eremascus might almost belong to the Mucorini (Piptocephalideae), 

 while on the other hand it is not wanting in the essential attributes of 

 an Ascomycete. In the form of its sexual organs it completely resembles 

 Penicillium, Gymnoascus, Eurotium, &c. Again, great agreement is to 

 be recognised between the thallus, spores, and sexual organs of the 

 Erysipheae (Podosphaera especially) and those of the Peronosporeae. 

 The resemblance ceases with the farther development of the results of 

 sexual union, and at this point the groups diverge from the point of 

 contact of Eremascus and Podosphaera with the Mucorini and Perono- 

 sporeae. Of course the envelope-apparatus of the asci is not included in 

 any comparison, as being of purely secondary importance ; and since such 

 envelope is actually wanting in Eremascus x , the case is made the clearer. 

 It is also pointed out that though the oogones of the Peronosporeae have 

 no envelope, it is by no means impossible that such may be found, while 

 the zygosperms of Mucorini, as has been shown, are sometimes provided 

 with an envelope. On such evident grounds as these, cited from de 

 Bary ('Comp. Morph. and Biol. of Fungi,' p. 232), who enters minutely 

 into the matter (as well as the subject of the sexuality of the Ascomy- 

 <?etes), the relationship of these groups with each other is abundantly 

 established. 



DOUBTFUL ASCOMYCETES. 



i. LABOULBENIE^E. The Laboulbenieae are a small assemblage of 

 remarkable parasites on insects, attacking mostly water-beetles, but also 

 other insects, including the house-fly. They possess no mycele, and 

 occur fixed on the chitin of the insect attacked by means of a short 

 process which serves as a haustorium, if that name may be applied to it. 

 Above this rises a stalk consisting usually of two cells, one above the 

 other, bearing at the summit a simple perithece and a few lateral hairs 

 (the appendage] composed of seriated cells sometimes having minute 

 round swellings at their apices. Before the complete development of the 

 perithece has been reached, there is emitted from its summit a short fine 

 process, which may be a trichogyne ; and according to Karsten (Stigma- 

 tomyces, Karst.) the minute round swellings on the hairs become free and 

 attach themselves to the trichogyne. Doubt, however, has been cast 

 upon the accuracy of this observation by the investigation of Peyritsch, 

 who also attaches no great value to the suggestion that the so-called 



