396 



PVNGI 



mycetps, the one being an approach to gymnocarpous forms, and the 

 other noteworthy in respect of its stalked and pileate appearance. 

 De Bary, in comparing the groups, says ('Comp. Morph. and Biol,' 

 P- 337) : ' If ^'e could attribute a decisive value to the habit of the 

 plants, we should dwell upon the great resemblance between the stalked 

 Hymenogastreae, Uke Secotium erythrocephalum (Tul.), and a veiled 

 Boletus. . . . But among the Polyporeae there is a remarkable form 

 Polyporus volvatus (Pk.), the Polyporus obvallatus (Berk, and Cooke), 

 which considered by itself must be placed with or close to the Hyme- 

 nogastreae. Its sporophore, which lives in the bark of trees, is a hollow 

 Spherical body flattened at the poles and about the size of a hazel nut, 

 with a thick closed wall of leathery texture ; its interior surface is 



Fig. 325. — Batarrea Steveni Fr., longitudinal sections. 



a, a younger specimen, but with most of its spores ripe 



b, a mature specimen, of which only apex and ba«;e are 

 shown, p and A, the outer, i, the inner peridium ; ^, 

 the glebe (one-third natural size). (After de Bary.) 



Fig. 326. — Batarrea Steveni Fr. 

 Isolated threads of the capillitium 

 ( X 390). (After de Bary.) 



covered with the hymenium of a Polyporus on the part next the sub- 

 stratum, and is sterile on the opposite side.' 



In the Lycoperdace^ (Puff-balls) the peridia are often developed to 

 a colossal size, and in structure they agree in the main with the Hyme- 

 nogastrese. The chief distinction lies in the existence of two kinds of 

 hyphae in the trama ; slender segmented hyphse with dense protoplasmic 

 tontents, the terminal members of which compose the hymenium, and 

 stouter hyphfe running not only in the trama, but crossing the chambers. 

 Eventually the slender hyphse and the hymenium disappear, leaving only 

 the stout hyphse, now called the capillitium, and the masses of spores 

 between. As examples of the possession of both inner and outer peridium 

 in this section, there may be cited Geaster (Mich.), in which the outer one 



