45 



whatever its form, is pushed up only to the surface of the earth, 

 as in the Puff-balls; at others it is entirely subterranean, when the 

 sporophore must decay before the spores can be liberated, as in 

 the Truffle. 



At times the young sporophore is completely covered by a soft 

 covering, which ruptures as the plant pushes upwards, sometimes 

 to leave a cup at the base of the stem and fragments upon the 

 cap, as in the Amanitas; at others to leave a mere remnant in the 

 shape of hairs on cap and stem, as in Cotinarius. In most of the 

 mushrooms this outer covering is completely lacking. As the 

 sporophore grows, it commonly becomes differentiated into a stem, 

 and a cap surmounting the stem. Under this cap (see chart), in 

 the Agaricacese, the Polyporacese, and in most of the Hydnaceae, 

 peculiar organs are developed to support the spore-bearing surface 

 or hymenium. In the Agaricacese the hymenium is spread over 

 flat plates, which radiate from the center, and are called gills. In 

 the Polyporacae, tubes, cylindrical or quite angled > take the place 

 of gills. In the Hydnaceae the spore-bearing surfaces are ex- 

 tended into long or short spines. For the characters of those 

 other families of the Hymenomycetes. see the chart. The re- 

 mainder of the cap, supporting the hymenium, is known as the 

 hymenophore, a name signifying "hymenium supporter." Pro- 

 jecting from the gills, or other kinds of spore-bearing surfaces, 

 are found, under the microscope, peculiar bodies like Indian clubs, 

 called basidia. These basidia bear on their extremities spores, 

 varying in number in the different families, but ordinarily four, 

 and raised above the basidia on little sharp points, known as the 

 sterigmata (singular "sterigma"). In many of the Agaricaceae 

 and Polyporaceae the hymenial surface is protected in its early 

 growth through the earth, and in some cases to near full matur- 

 ity, by a kind of curtain, which joins the edge of the cap to the 

 stem, and is known as the veil. As t e plant reaches maturity, 

 this veil is ruptured by the lateral growth of the cap, and a part 

 of it may hang from the edge of the cap, or, as is most usually 

 the case, the greater part of it may be left adhering to the stem as 



