452 COMPARATIVE MORPHOLOGY OF FUNGI 



with those at the edge of the stipe. Here belong some Hygrophoraceae 

 and Clitocybeae. 



In the middle stage the fundament of the pileus is always rolled up 

 and its edge remains connected with the stipe primordium. Thus in 

 the interior of the tissue an annular furrow, often with several chambers, 

 encircles the fructification; in it the hymenophore is formed (endogenous, 

 angiocarpous). The thin tissue, in the layer from the ground tissue 

 connected to the stipe rind, which separates this cavity from the exterior 

 and which, in a certain sense, is a continuation of the retroflcxed margin 

 of the pileus, is called the partial veil or inner veil (Fig. 293, A, vp). It 

 is frequently evanescent. At maturity when the pileus expands by 

 strongly hyponastic growth and general elongation of its hyphae, the 

 partial veil is torn to shreds. Its remnants separate into threads and 

 disappear, and only an ontogenetic investigation can show its original 

 presence. Such an evanescent partial veil is found in many Lactariaceae, 

 Marasmieae and Coprinaceae. In other cases, the partial veil acquires, 

 from the edge of the pileus and from the stipe, new hyphal elements and 

 consequently forms a stronger structure. Thus, in the expansion of the 

 pileus, it is retained as such and is either loosened from the edge of the 

 pileus (Fig. 293, a), or from the stipe. In the first case, it remains with 

 the stipe in the form of a closely attached collar which is called the inferior 

 annulus or ring. In the second case it remains hanging from the edge of 

 the pileus; these remnants are usually called cortina. In some forms it 

 is first loosened from the stipe, then from the margin and remains as a 

 movable ring surrounding the stipe. The ring occurs in Armillaria, 

 Psalliota and Amanita, a cortina in Cortinarius and Hypholoma, and a 

 movable ring in a few species of Coprinus and Lepiota. 



In the highest stage, finally, a cortical layer of mostly thick-walled 

 hyphae, the membranous or blemmatogenous layer, is differentiated on 

 the whole outer surface of young button. In most cases, as in the Tricho- 

 lomeae and the Amaniteae, it remains connected with the tissue under- 

 neath (especially with the cortex of the pileus and the partial veil) and 

 is only recognizable in cross-sections of young stages by its different 

 appearence and staining capacity. At times it cannot follow the expan- 

 sion of the pileus and remains on the pileus, as scales or as a powder or 

 becomes a gel. In some genera, as Amanita, Amanitopsis and Volvobo- 

 letus, it is separated from the rest of the pileus by a swelling, sharply 

 defined tissue and remains then in connection with the base of the often 

 bulbous stipe only : this special peridial membrane surrounding the whole 

 fructification like an egg shell, is called the teleblem (Fig. 293, B, 

 vu). In individual cases it is covered by a loose flocculent layer which 

 is called the primary universal veil or protoblem. The universal veil, 

 not being able to follow the elongation of the stipe and the expansion of 

 the pileus, is torn to pieces and then remains behind at the base of the 



