﻿19 1 6] ATKINSON— COPRINUS 93 



as the species of Agaricus, Armillaria, and Lepiota studied by the 

 writer are concerned, it can be most positively reaffirmed, that, 

 first, there is a general, annular, prelamellar cavity; second, a 

 general palisade layer over the roof of this cavity precedes the 

 origin of the lamellae; and third, the first radiating ridges or folds 

 of the hymenophore are the fundaments of the lamellae themselves. 

 The primary ridges or folds do not split to form the lamellae 

 between them by the union of approximate halves of adjacent 

 ridges. From the plants already studied, the writer has never 

 formulated any generalizations as to what the situation may be in 

 any other species or genera, in regard to the presence, either of 

 a general annular gill cavity, of a palisade layer, or the origin of 

 the gills. Without any bias, therefore, we may proceed to the 

 interpretation of the situation in the three species of Coprinus 

 which are the subject of the present paper. 



Material 



The material for study was collected in September 1914, all of 

 it. with the exception of a few not very young specimens of Coprinus 

 atramentarius, on the campus of Cornell University. It was fixed 

 in chromacetic acid. 



Coprinus comatus. — Two different collections were made of this 

 species. The first lot of material was collected early in September 

 in comparatively new made ground by the edge of a small bed of 

 recently planted shrubs at the west end of Roberts Hall. A 

 single plant had just emerged from the soil, and the aspect of the 

 surroundings indicated that the colony was new and young. The 

 mycelium was abundant and extended through the soil, partly in 

 the cultivated portion, and partly in the newly made sod, for an area 

 of less than 1 m. in extent; 20-25 young fruit bodies were col- 

 lected from this area. The second lot of material was collected 

 the latter part of September in a grassy plot east of Sage College. 

 Here a number of mature plants had sprung up, but several very- 

 young ones were found scattered on the mycelium in the soil some 

 distance from the old specimens. 



The specimens were not growing in clusters, but scattered on 

 the strands of mycelium. In the young material it was impossible 



