284 COMPARATIVE MORPHOLOGY OF FUNGI 



placodium belonged to the entostroma, here it is supplied by the ecto- 

 stroma; hence the first genus is called entoplacodial, the latter 

 ectoplacodial. 



In Pseudovalsa there is no definite ectostroma and where a stromatic 

 mycelium is formed, it is within the bark about the perithecial necks. 

 Where the entostroma develops, there is a faint, dark, marginal zone, but 

 the entostromatic mycelium is usually dark colored, hence the stromatic 

 areas are not light as in Diaporthe. The imperfect stage is ectostromatic, 

 but is usually not connected with the perithecial stroma, or where it is, 

 as in some species of Pseudovalsa, the ectostroma is reduced. 



Diaporthe Wibbei, var. Comptoniae on Myrica asplenifolia, forms a 

 transition from Diaporthe to Pseudovalsa, showing no marginal zones in 

 the substrate, and producing septate, appendiculate conidia. In the 

 stromatic tissue, loose ends of hyphae appear at one or several points 

 and cut off conidia until a central, spherical or irregular cavity with a 

 peripheral hymenium of conidiophores results. The subhymenium acts 

 as a nurse tissue to the conidiophores. The connection of conidium and 

 conidiophore becomes constricted and elongate. The conidium is 

 abjointed at the apex of this elongate tip. The next conidium is con- 

 stricted somewhat back of the apex of the conidiophore. The growth 

 of the portion of the conidiophore above this constriction gives rise to the 

 spore while the elongation of the stalk of the previous conidium forms 

 the apical appendage. This conidial stage was described as Pestalotia 

 flagellifera (Barclay ella flagellifera, Neobarclaya flagellifera). The peri- 

 thecial stroma lacks an ectostroma and the blackened zones, while the 

 entostromatic hyphae develop about the perithecia, suggesting the 

 simpler species of Pseudovalsa (Wehmeyer, 1928). 



In Pseudovalsa lanciformis on dead branches of Betula alba, the ento- 

 stroma is entirely absent. The hyphae connect inside the bark into a 

 tangled stroma which at first cuts off conidia on its surface (Coryneum 

 disciforme) , then ruptures the periderm and forms ascogonia and 

 perithecia. 



In the second series, the main line of development in Cryptosporella 

 and Cryptospora shows a similar stromatic structure and similar imperfect 

 stage. The relationships among the lower forms are still vague. Gno- 

 moniella has no stromatic development and may be considered as an 

 ancestral form. Sphaerognomonia shows the development of a stromatic 

 "clypeus" about the ostiole while Mamianiella shows a well-developed 

 stroma about the perithecium. These three genera are found on leaves. 

 Mazzantia (Hoehnel, 1918) has a stromatic structure identical with that 

 of a well-developed Diaporthe, but it has unicellular ascospores. 

 M. Gallii has a well-developed, differentiated entostroma within the tissue 

 of the substrate, bounded by a darkened zone. The cylindrical, hyaline 

 conidia are borne in an enclosed locule within the stroma. 



