296 CHAPTERS ON FUNGI. [Octobev, 



and inconspicuous, except in the larger and more perfect kinds, 

 in which they are sometimes developed to a considerable extent. 



The pileus is generally of a rounded or orbicular shape, and 

 varies in being hemispherical, flat, campanulate, etc. Its flesh, 

 or substance, is sometimes very thick, and sometimes hardly ap- 

 pears at all. It varies a good deal in texture also, being soft, 

 coriaceous, membranaceous, etc. 



The hymenium assumes various forms : in the large and ex- 

 tensive genus Agaricus it appears in the shape of lamella, or gills, 

 which radiate from the stem to the margin of the pileus. In 

 Boletus and Polyporus it assumes the form of tubes and pores, 

 and in the Hydnum and others that of spines, or teeth; and 

 there are various modifications of these forms. 



The spores in the genus Agaricus are produced on the surface 

 of the gills. They are normally borne on sporophores, and are 

 sometimes arranged in groups of four. In Boletus, Polyporus, 

 etc., they are also produced on the surface of the tubes or pores, 

 etc., but do not appear to be definitely arranged. 



The stipes is in some instances much developed, and in others 

 is wanting, or nearly so, when the pileus is said to be sessile. It 

 varies in being solid, hollow, bulbous, etc. 



Sometimes the whole Fungus, in its young state, is enclosed in 

 a volva, or membranous bag, which remains at the base of the 

 stem after the plant has burst through it and shot up to matu- 

 rity, and in other cases the margin of the pileus is connected 

 with the stem by a membrane of greater or less density, called 

 the veil [velum] , and serving to cover and protect the gills in their 

 young state. This appendage is generally ruptured during the 

 growth of the plant, and the remains of it often form a collar or 

 ring [annulus] round the stem. Sometimes both the volva and 

 annulus are found in the same plant. 



I have been somewhat particular in the description of the above 

 forms, as they are the most perfect ones assumed by Fungi, and 

 as they occur in a large number of our British species. There 

 are many modifications of them however as we descend in the 

 scale. 



In some genera, as Thelephora, etc., we find the pileus and 

 hymenium united, and forming one homogeneous body, and the 

 hymenium, which is often resupinate, generally smooth and scat- 

 tered over with little tubercles {papilla;). The Thelephora and 



