540 CLASS BASIDIOMYCETEAE 



terranean at maturity and reaches a diameter of 5 to 20 mm. The glebal 

 chambers are at first filled with large spherical cells which then gelatinize. 

 Long hyphae traverse these cavities and on them sit the long, slender 

 basidia which bear 5 to 11 pale brown, almost sessile, ellipsoid, smooth 

 spores. Dodge (1931) who described the genus considered it to belong to 

 the Rhizopogonaceae, a family segregated from the Hymenogastraceae, 

 and including a number of genera placed by Fischer in the Melanogas- 

 traceae. Zeller (1939) held that its development suggests closer relation- 

 ship to the latter family than to Rhizopogon. 



Family Hydnangiaceae. In this family of Hymenogastrales the 

 coralloid development of the gleba has become unipileate. Like Hemigaster 

 the spore fruits are pseudoangiocarpic in their development. The upper 

 portion of the stipe becomes the percurrent columella. Unhke Hemigaster 

 the palisade layer of the under side of the recurving pileus is thrown into 

 folds which anastomose with one another and with the columella so that a 

 multilocular gleba is produced. The columella may become reduced with 

 age to a slender, scarcely recognizable strand, in some species. The stipe 

 below the pileus is represented by only a small projection, if visible. 

 Cystidia and spiny basidiospores two to four per basidium on long sterig- 

 mata are found in Hydnangium and Arcangeliella. In the latter genus 

 laticiferous tubes are present. In Chamonixia the spores are longitudinally 

 ribbed, much as in Gautieria. 



Family Secotiaceae. In this family the general plan is much like that 

 of the preceding one, but the stipe is more pronounced in most forms. 

 Development is pseudoangiocarpic in Elasmomyces and angiocarpic in 

 most of the remaining genera. Elasmomyces represents probably an inter- 

 mediate form between Hydnangium and Secotium. The fruit body is 

 mostly eventually epigeous. Its development is pseudoangiocarpic like 

 that of Hydnangium. In the tissue of the stipe are nests of enlarged, 

 bladder-like cells, resembling those of Russula in the Agaricaceae. The 

 spores are marked with verrucosities, sometimes connected by ridges, as in 

 Russula, and as in that genus they are stained blue with reagents contain- 

 ing free iodine. Bucholtz (1903) considered these two genera, as did 

 Malengon (1931), to be closely related. Heim (1938) also emphasizes the 

 relationship of Lactarius and Russula to Elasmomyces. 



The genus Secotium, with which Elasmomyces is sometimes united, is 

 angiocarpic in its development in the species studied (*S'. agaricoides 

 (Czern.) Hollos, by Conard, 1915, S. novae-zelandiae Cunningh. and *S'. 

 erythrocephalum Tul., by Cunningham, 1924 and 1925). (Fig. 174.) In the 

 earlier stages of development it shows great resemblance to that of 

 Agaricus (Atkinson, 1906, 1915), but instead of forming radial lamellae 

 separating the annular opening into radial cavities the tramal plates are 

 irregular in the direction of their growth and anastomose to form closed 



