SUMMARY
1. | Secotium agaricoides is a widespread species, occurring in Europe, Asia, Africa, North America, Australia, and New Zealand. | ||||
2. | In the young carpophore, the fundament of the hymenophore first appears, followed by the demarcation of the margin of the pileus and the appearance of a gill cavity. | ||||
3. | The development of the “peridium “ is like that of the cap of Agaricus campestris, showing a primitive velum universale and a pileus. No true velum partiale is found, though a layer of “neutral tissue” occurs which may represent it. The universal veil disappears during the maturation of the plant. | ||||
4. | The hymenophore consists of radiating, branched, and anastomosing gills decurrent at the top of the columella. | ||||
5. | The trama and hymenium are simple in structure, without pseudoparenchyma or cystidia. | ||||
6. | The young basidium has two nuclei, which unite to form one. This latter divides twice to form four nuclei for the four spores. The mycelial cells are binucleate. | ||||
7. | Secotium agaricoides is nearly related to Agaricus (Psalliota), being an arrested or paedogenic form. It is not closely related to the Gasteromycetes or Phalloids. |
The author is indebted to the Botanical Department of the State University of Iowa for a loan of high power lenses, and to the management of the Missouri Botanical Garden for the use of books. These favors are gratefully acknowledged.