282 H. MAESHALL WAED. 



sclerotic rum forms its asci and paraphyses in a purely 

 vegetative manner. At any rate, apogamy must be regarded 

 as occurring iu these Discomycetes, and as being attained 

 gradually through a series of forms. 



Before referring to other work of Kihlmann's I wish to 

 review an important paper by Fisch,^ published in 1882. In 

 this are detailed the development of the fructification of several 

 Ascomycetes which form a stroma, in which the proper 

 perithecia are buried, more or less. He is clearly acquainted 

 with the recent researches and speculations of De Bary, and, 

 in fact, worked in his laboratory. Very little has been done 

 with regard to the Fungi mentioned, and so careful a paper as 

 this is especially welcome. The Fungi examined by Fisch are 

 Polystigma, Xylaria, Claviceps, and Cordiceps. 



Polystigma occurs in the leaves of Prunus," forming 

 swollen masses. The formation of the ascospores takes place 

 some months after the fall of the leaf. The ascospores, sown in 

 water, produce secondary spores. These send hyphae through 

 the epidermis of the living leaf, and a mycelium is formed in 

 the intercellular spaces. This breaks down the cells in part, 

 or stimulates them to hypertrophy, and thus the stroma is 

 formed, partly of mycelium, partly of hypertrophied leaf-tissue.'^ 

 Eight weeks after infection, the young spermagonia appear as 

 knots of hyphae, which become hollow and abstrict the spermatia. 



The young perithecia now arise as small clumps of fine 

 hyphae, which soon form a sub-globular mass, and in the 

 interior of which a spirally-coiled group of cells represents the 

 ascogonium, and reminds the observer of the ascogonium of 

 the Collemaceae.^^ This body is somewhat irregular, not evi- 

 dently attached to a particular part of the mass enveloping it, 

 and it slowly grows as the surrounding perithecium cells 

 multiply. 



1 "Entw. einiger Ascomyceten," 'Bot. Zeit./ No. 49, 1882.^ 



2 Cf. Frank, 'Krankheiten der Paanze,' p. 632. 



^ Cf. Tulasne, * Selecta -Fung. Carp., iii, and De Bary, ' Morph. und Pliys. 

 der Pilze, &c.,' p. 8 ; also Frank, loc. cit. 

 * Stalil., op. cit. 



