AGARICUS ARVENSIS AND A. COMTULUS 
II 
(AgaricMS ruhellus Gillet) as figured by Fayod^ (1. c, pi. 7. fig. 4) which 
he places in his subangiocarpous type {''type suhangiocarpJ' pp. 284, 
285) to which he says the majority of the species of Psalliota {Agaricus 
as limited here) probably belong. In this type, according to Fayod, 
the universal veil is not differentiated from the cuticle of the pileus but 
remains concrete with the pileus as stated by Fries^ for the species of 
his Tribe Lepiota. In the subangiocarpous type Fayod interprets the 
universal veil (voile generale) to include the partial veil, the outer 
layer of the carpophore continuous with the partial veil, together 
with the fundamental tissue which separates from the stipe. It 
would include the outer zone of the mature pileus, since the universal 
veil, according to this interpretation, does not separate from the 
pileus but remains in intimate union with it. 
A primary universal veil in Agaricus campestris. — In Agaricus 
campestris there is often formed a well differentiated, but delicate and 
floccose, universal veil,^^ quite distinct from a very young stage, which 
at maturity separates distinctly from the surface of the pileus. It is 
as strongly developed as the universal veil which is present in Pholiota 
caperata on which Karsten based his genus Rozites}^ But in this 
species there is a definite pileus cuticle or cortex of specialized cells, 
forming a clear and distinct differentiation from the universal veil. 
In Agaricus the cuticle of the pileus is fibrous and not specialized. In 
other species of Agaricus a similar delicate universal veil is sometimes 
present. What I have heretofore regarded as the universal veil in 
Agaricus campestris is this outer layer of loose fundamental tissue. 
It is a primary universal veil, evident on the young carpophore, and 
which can be seen in sections at later stages as a thin loose layer 
enveloping pileus and partial veil, though not separated so cleanly 
from the carpophore as in the genus Amanita where the universal 
veil is usually much stouter, and not strictly homologous with the 
freed portion in Agaricus campestris. 
Organization of pileus surface. — In no one of the three species of 
Agaricus which I have studied does the pileus surface, during its 
* Prodrome d'une histoire naturelle des Agaricines. Ann. Sci. Nat. Bot. VII. 9: 
181-411. pis. 6, 7. 1899. 
9 Syst. Myc. 1: 19. 1821. 
Atkinson, Geo. F. The development of Agaricus campestris. Bot. Gaz. 42: 
241-264. pis. 7-12. 1906. 
Karsten, P. A. Rysslands, Finlands och Skandinavikar Holfans Hattsvampar. 
.1:290. 1879. 
