Notes on the Development of the Carpophore of 
some Agaricaceae. 
BY 
RUDOLF BEER, B.Sc., F.L.S. 
With Plate LII. 
HE exact order and manner in which the different parts of the carpo- 
X phore develop is still uncertain in a large number of Agaricaceae. In 
his earlier work De Bary ( 1 ) attributed an internal origin to the hymenium of 
Agaricus (. Psalliota ) campestris and some other Agarics which he had studied. 
In 1874, however, Robert Hartig ( 3 ) described the development of the carpo¬ 
phore of Agaricus (Ar miliaria) melleus , and he found that the pileus arises 
through a superficial annular furrow which in the beginning is completely 
open to the outside, and that later, through growth of the marginal hyphae 
of the pileus and of the stem, the annular furrow becomes covered over with 
a hyphal layer, the veil. 
In his ‘ Comparative Morphology and Biology of the Fungi, &c./ pub¬ 
lished in 1884, De Bary ( 2 ) renounces his former opinion and accepts that of 
R. Hartig. He now believes that in Agaricus campestris , as in A. melleus , 
the primordium of the hymenium is first exposed in the open annular 
furrow which marks off the rudimentary pileus from the stem, and that 
only subsequently it becomes enclosed by hyphae, which grow towards one 
another from the edges of the furrow and form the marginal veil. 
Fayod ( 4 ) studied a very large number of Agaricaceae, and he concluded 
that the primordium of the pileus was always the first to be differentiated 
within the rudiment of the carpophore. It arises as a definite layer, the 
‘ couche pileogene/ which has the form of a shallow inverted bowl, convex 
above and concave below. This is surrounded externally by a thin layer 
which he calls the ‘ cuticule primordiale \ Fayod divides the Agaricaceae 
into angiocarpous, subangiocarpous, gymnocarpous, and endocarpous forms, 
and he attempts to trace his 4 cuticule primordiale ’ in all of them. He very 
obviously, however, brings together several very different structures under 
the one name. For seventeen years after the publication of Fayod’s work 
[Annals of Botany, Vol. XXV. No. XCIX. July, igu.] 
