THE ORIGIN AND DEVELOPMENT OF LAMELLAE IN 
AGARICUS CAMPESTRIS AND IN CERTAIN 
SPECIES OF COPRINUSi 
Michael Levine 
(Received for publication March 3, 1922) 
Introduction 
The history of the study of the development of the Basidiomycetes 
dates back to the earlier part of the nineteenth century. Nees von Esenbeck 
(18 16) should be credited with the description of the origin and develop- 
ment of these plants based on a philosophical conception of how they should 
develop rather than how they actually develop. Yet many writers, such 
as Dutrochet (1837), Trog (1837), and others, coupled these notions of 
Nees von Esenbeck with some actual observation. They were able to 
distinguish the two essential stages in the life of the mushroom, namely, 
the vegetative and the reproductive. 
Toward the middle of the last century, Schmitz (1842)^ first described 
an annular gill cavity separating pileus and stipe in several species of 
Basidiomycetes and was the first to recognize the veil or cortina. Schmitz 
conceived a method of development for all pileate fungi in which the organ 
nearest the substratum in the mature form is the structure first to develop, 
so that the mycelium is developed first, the stipe second, and the pileus 
next, the hymenophore being formed last. 
Bonorden (1851), working about the same time, was the first to describe 
the structure of the volva and the manner in which dehiscence is effected. 
He contributed nothing to the origin of the parts of the plant. 
Hoffmann's (1856) observation of the development of the carpophore 
lies at the basis of many current accounts of the methods of formation of 
the pileus and hymenium. He described the young buttons of Agaricus 
campestris as small spheres which elongate owing to the growth of the 
interior cells perpendicularly upward. The terminal cells now grow out 
laterally and then turn abruptly downward; the ends of these hyphae 
form the primordia of the lamellae. In i860 and 1861 Hoffmann described 
the development of seventeen different species of higher Basidiomycetes. 
He contends that the fungus first appears in the form of a small white 
sphere in which a deeply colored central portion of the pileus rudiment 
^ The author wishes to express his indebtedness to the Carnegie Institution of Wash- 
ington for assistance with the publication of the illustrations. 
2 Schmitz studied Coprinus niveus, Cantharellus sinuosus, C. tubeaformis, Agaricus 
Bulliardi, and Hydnum imhricatum. 
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