AGARICUS ARVENSIS AND A. COMTULUS 
17 
and may be said therefore, to be concrete with it. But the evidence 
of the presence of a "universal veil" and its relation to the pileus is 
not so clear as in Lepiota clypeolaria. 
Comparison with the Amanitae. — In the Amanitae, "the universal 
veil," quite prominent even in the young carpophores, is still not 
precisely differentiated in Amanitopsis vaginata,^^ not more so than in 
the young carpophores of Agaricus arvensis and Ag. comtulus. 
When the pileus surface is quite well organized in the Amanitae 
there is a zone of parallel hyphae between the pileus and universal 
veil which gelatinizes, or disintegrates in other ways, and separates 
the universal veiP^ clearly from the pileus. The position of the partial 
veil in the Amanitae is such that at no time is there any question as 
to its distinctness from the "universal veil," though the fundamental 
tissue from which it originates is in contact with that of the universal 
veil at an early stage of the carpophore. It must be remembered 
that in the primordium of the carpophore, the fundamental tissue, 
from which all parts of the plant arise, is continuous and undifferen- 
tiable, but this does not mean that when organized the stem is to be 
considered a part of the pileus. 
Is there a primary universal veil, or protohlem, in A. arvensis and 
Ag. comtulus? — It is quite possible that, in the very young carpophores 
of Agaricus arvensis and Ag. comtulus, there is a primary universal 
veil, or protoblem, as in Agaricus campestris, and that it is represented 
in part by the thin exfoliated portions shown in figures 5, 6, 7, and 10. 
But in carpophores developing underneath the substratum, as these 
were, it is difficult to determine this point with precision. In speci- 
mens artificially grown, where the carpophores are exposed from a very 
young stage, as is often the case with Agaricus campestris in culture, 
it should not be a difficult question to settle. 
Double margin of the partial veil. — In Agaricus as epinastic growth 
inrolls the margin of the pileus, the increase of the fundamental tissue 
of the partial veil often covers the external surface of the inrolled 
pileus margin. In such cases, as the pileus expands and the margin 
separates from the edge of the partial veil, the latter presents two 
edges. When the veil is quite tumid and not broad, and the margin of 
the pileus is very thick as in Agaricus campestris var. edulis,^^ or in 
21 The development of Amanitopsis vaginata will be published in another paper. 
22 Now a complete or finished veil, or teleoblema (tcXcios = complete or finished, 
Pkniia = cover). 23 Vittadini, G. Fung. Mang. 41. pi. 6. 1835. 
