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Mycologia 



bonaceous and open by a cleft rather than by an elliptical ostiole. 

 In order to determine whether the internal structure might throw 

 light on the true systematic position of the genus, microtome sec- 

 tions of Acrospermum compressum and of a new species have 

 been studied and have yielded certain results of interest. Ref- 

 erence to figure ii will show that the lower part of the fructi- 

 fication is occupied by sterile tissue. This is more or less pro- 

 senchymatous in nature, differing from the substance of the wall , 

 and reminding one of the hypothecium or trama of a normal 

 apothecium. Nevertheles, this does not necessarily indicate dis- 

 comycetous affinities, for a similar structure is found in the 

 perithecium of some Pyrenomycetes, for example Bombardia 

 fasciculata Fr. Figure 12 illustrates the apical portion of the 

 fructification somewhat more enlarged. It will be noticed that 

 the paraphyses do not form a definite hymenium such as would 

 be found in the Hysteriales, but that they converge loosely toward 

 the ostiole rather in the manner of various Pyrenomycetes. 

 Taking this into account together with the texture, and with the 

 facts that a compressed form and elongated ostiole are found in 

 the Lophiostomaceae, and a sterile basal tissue in Bombardia 

 and other genera, it would seem to the writer that the natural 

 conclusion is to consider the fructification a perithecium and to 

 follow Ellis in placing the Acrospermaceae not under the Hys- 

 teriales but under the Hypocreales. 2 



Material distributed in the principal exsiccati under the specific 

 name Acrospermum compressum Tode shows considerable varia- 

 tion (compare Figs. 7-10). The size varies from 0.8 to 2.5 milli- 

 meters. The form varies from spatulate, with the apex almost 

 truncate (Fig. 8) to clavate with an obtuse apex (Fig. 10). The 

 figures cited show a corresponding variation in the development 

 of the stipe : in such perithecia as are figured in Nos. 7 and 8 

 there is merely a slight contraction below, scarcely to be referred 



2 Owing to delay in the receipt of German journals, because of the war, the 

 present paper was in print before the writer saw a note by Von Hoehnel in 

 the Annates Mypologici (15: 379. 1917), in which he expresses the view that 

 Acrospermum is undoubtedly one of the Pyrenomycetes. Von Hoehnel be- 

 lieves that the characters in common with Bombardia indicate true relation- 

 ship, and after naming two probable connecting links, he places Acrospermum. 

 in the Sordariaceae. 



