128 THE VICTORIAN NATURALIST. 



ways ; but in all these cases the spore is produced free, or, as 

 it is called, naked. 



In the other great division, the spores are produced in tiny 

 bags, called asci. An ascus is shaped like the ancient spindle — 

 that is, cylindrical, but gradually decreasing to a point at either 

 end. The asci generally contain eight spores, each placed side 

 by side, and are thus, as it were, concealed, in contradistinction 

 to the naked spores of the other division. Turning again to the 

 naked spored division, we have the following groups : — 



(i.) Hymenomycetes, when the hymenium or spore-bearing 

 membrane is free, as in the common edible mushroom, where the 

 hymenium covers the gill-like substance beneath the cup, or 

 pileus, as it is called. 



(2.) Gasteromycetes where the hymenium is at first enclosed 

 in a fleshy bag as in the common puff-ball, which soon bursts, 

 allowing the spores to disseminate. Before proceeding it would 

 be well to explain exactly what the hymenium is. Imagine an 

 exceedingly thin membrane from the one surface of which arises a 

 great number of cells, exactly as a great number of plants of wheat 

 may rise from the upper surface of the wheat field. Amongst 

 these cells may be remarked small sterile cells, large sterile cells, 

 and basidia. A basidium is a fruitful cell rising from the top of 

 a short stem, and its growth will be explained more fully when 

 describing the Calocera. This hymenium in the plants belonging 

 to the Hymenomycetes covers the whole of the under surface of 

 the pileus, whether that surface may consist of gills, or pores, or 

 teeth, on an irregular but smooth surface, or it may cover the 

 upper portion of the plant ; but in the Gasteromycetes the 

 membrane or hymenium is compressed in such a manner as 

 you might crumple up a sheet of soft paper, and in this shape 

 is placed within a cover or peridium. The other two groups of 

 the naked spored division are distinguished by the hymenium 

 being broken up into dust-like spores, with very few threads, 

 or with very conspicuous threads bearing, comparatively speaking, 

 few spores. Our subject only deals with the first group. 



The Hymenomycetes contain four sub-orders which have the 

 hymenium normally inferior, such as in the common Agaricus, 

 where it is placed below the cap, or pileus. The Hymenomycetes 

 comprises two other sub-orders, in which the plants have no pileus 

 and the hymenium encircles the upper portion of each stem or 

 branch, reaching in every instance to the apex. These two sub- 

 orders are named Clavariei and Tremellini, and it is with these that 

 our subject matter is closely connected. Those of our members 

 who are in the habit of attending the field excursions must 

 have observed beautiful coral-like plants of various colours — red, 

 yellow, brown, or white ; these are all different species of Clavaria. 

 They are always erect, and, as their name implies, club-like in 



