284 M. C. Montagnc's Organography and Physioloyic 



species, there appear upon the mycelium one or more little ovoid or 

 spherical tubercles, whose successive increase shows what species we 

 have before us ; for at first all are concealed under a more or less 

 dense spidery web, which the greater part cast off before completing 

 their evolution, but in which some always remain enveloped. In 

 this respect we cannot overlook the striking analogy which exists 

 between the whole class of Fungi and that of insects, an analogy al- 

 ready recognised and pointed out by the illustrious Fries. The veil 

 with which I said the tubercles were covered is sometimes woven 

 into a membrane of greater or less thickness, and more or less tough, 

 which, after having enveloped the fungus, as the elements of an egg 

 in its shell, at last bursts at the summit or on the side, and gives it 

 free access to air and light. This membrane, which is called volva 

 (velum universale), frequently remains at the base of the peduncle, 

 and then affords excellent characters for specific distinctions. Some- 

 times it bursts circularly around the pileus, and its upper hemisphere 

 glued to its surface, forms spots or discoloured warts, as in Agaricus 

 muscarius. In other cases it is entirely resolved into persistent 

 scales. Sometimes it is formed of a byssoid web so delicate that not 

 the least trace is to be found. Besides the volva, which is wanting 

 in many genera, many Hymenomycetes are supplied with a second 

 envelope, which, after its rupture, remains frequently upon the pe- 

 duncle under the form of a collar or ruffle ; this is called a ring (ve- 

 lum partiale). It is complete when it encloses the whole pileus ; in- 

 complete when, being fixed on its border, it covers only the gills. 



The ring, which is generally white, is membranous or arachnoid, 

 persistent or fugacious, adhering to the peduncle, or free and move- 

 able. Its upper or inner surface has frequently striae which corre- 

 spond to the gills with which it has been in contact. It is fixed at 

 different heights upon the stem ; most frequently at about a third 

 from the top. But the partial veil is not always membranous ; in 

 one tribe of the genus Agaricus, an arachnoid web unites at first the 

 border of the pileus to the stem. This extremely delicate web, which 

 is named curtain (cortina), is composed of white or coloured threads, 

 and leaves traces of its existence either on the stem or on the mar- 

 gin of the pileus. 



The peduncle or stem (stipes) is that part of the fungus which, 

 when it exists, springs immediately from the mycelium and supports 

 the pileus. Its presence is not essentially necessary, since it is 

 wanting in many species, which are therefore named apodi or resu- 

 pinate. In those which are provided with it, it either occupies the 

 centre of the pileus, in which case it is called central (mesopus), or 

 else it is eccentric (excentricus) , or it is seated at the very edge of 

 the pileus (pleuropus). The stem may be cylindrical or fusiform, or 

 swollen and bulbous at the base, solid and stuffed, or fistulose, either 

 from the first or consecutively, smooth and uniform or flaky, tomen- 

 tose, villous, &c, annulate or ringless, same- or party-coloured, soft, 

 elastic, fibrous and tough, or even woody in certain species. 



When it is altogether wanting, or the pileus is attached imme- 

 diately to the matrix by a greater or less portion of the border, it is 



