54 THE GASTEROMYCETES OF THE UNITED STATES AND CANADA 



The genus seems to be particularly abundant in Australia and New Zealand, from 

 which Cunningham (1. c.) reports 16 species. He adds the following facts to our knowl- 

 edge of the cytology: 



"The hyphae of the columella, stipe and peridium are invariably binucleate. 

 The basidia at first are binucleate, these nuclei fuse, and a slightly larger fusion-nucleus 

 is formed. This takes up a position in the distal end of the basidium; there it divides 

 twice. The first division precedes the formation of the sterigmata, the second succeeds 

 their appearance. When the sterigmata are about half their normal length, spores 

 begin to appear on them, and when they are full length, the spores are about half size. 

 When the spores are about one-quarter their normal size, a nucleus migrates into each, 

 divides mitotically, and the spores become binucleate, a character constant in each 

 of the numerous species examined. The spore attains its full size before it changes 

 colour ; at maturity the epispore becomes coloured some shade of brown, the depth of 

 colour depending on the species. 



"Clamp connections are abundant in the tissues of the stipe and partial veil 



"On germination a germ tube protrudes, usually from the end of the spore oppo- 

 site to that by which it was attached to the sterigma; this branches repeatedly to form 

 a mycelium, the cells of which are septate and binucleate." 



Conard and Cunningham, working on different species disagree as to the presence 

 of a veil, Conard claiming the presence of universal veil and absence of a partial one 

 and Cunningham stating just the reverse. 



LITERATURE 



Conard. The Structure and Development of Secotium agaricoides. Mycologia 7: 94, pi. 157 and 1 



text fig. 1915. 

 Cunningham. A Critical Revision of the Australian and New Zealand Species of the Genus Secotium. 



Proc. Linn. Soc. of New South Wales 49: 97, pis. 12-15. 1924. 

 Cunningham. The Structure and Development of Two New Zealand Species of Secotium. Trans. 



Brit. Myc. Soc. 10: 216, pis. 11 and 12. 1925. 

 Lohwag. Entwicklungsgeschichte und systematische Stellung von Secotium agaricoides (Czern.) Holl. 



Osterr. Bot. Zeitschr., 1924, p. 161, pi. 2. 

 Setchell. Two New Hypogaeous Secotiaceae. Journ. Myc. 13: 236. 1907. 



Secotium agaricoides (Czern.) Hollos 

 S. acuminatum Montagne 

 S. Warnei Peck 

 S. rubigenum Harkness 



Plates 32 and 111 



Fruit bodies epigeal, solitary or gregarious, usually distinctly heart-shaped, rarely 

 subglobose, with a distinct conical or rounded stalk which tapers into a thick strand 

 and anchors the plant in the ground; very variable in size and shape, 1-5.5 cm. wide by 

 1.5-6 cm. high. Peridium nearly pure white when young and fresh, turning straw color 

 to cinnamon-buff or leather color upon maturing and drying; single-layered, 1-3 mm. 

 thick, nearly smooth in very young specimens, covered at maturity with inherent scales 

 which may resemble fish scales or may be very irregularly arranged; fleshy and tender 

 when young, becoming rather tough and fibrous upon drying. Gleba nearly pure white 

 when young, becoming yellow and finally brown; glebal chambers somewhat labyrinthi- 

 form, varying in width from a fraction of a millimeter up to 1 mm. Tramal plates 



