﻿VOLUME LXL 



NUMBER 



THE 



Botanical Gazette 



FEBRUARY igi6 



ORIGIN AND DEVELOPMENT OF THE LAMELLAE 

 IN COPRINUS 



Geo. F. Atkinson 

 (with PLATES v-xii AND SIX diagrams) 

 Introduction 



Members of the Agaricaceae thus far studied present two types 

 in the origin and development of the lamellae. In one of these 

 types, 1 which for the present we may speak of as the Agariais type, 

 the origin of the lamellae has been clearly described. It is pre- 

 ceded by the formation of a palisade layer of hyphae representing 

 a young stage in the development of the hymenophore on the under 

 side of the young pileus. This palisade layer of the hymenophore 

 is either accompanied by, or, in many of the forms described, pre- 

 ceded by a more or less well developed, general, annular cavity. 

 This cavity is, therefore, when present in the forms described, 

 prelamellar. It is formed by differences in tension on the tissue 



