132 
OBSERVATIONS ON TEZIZA. 
agglutinated laterally into scales, or forming an adpressed fibrous 
coat, or elongated into distinct hairs or bristles growing singly or 
in bundles, are all features which seem to be of importance. So 
also is the nature of the hairs themselves, whether simple, or 
forked, or stellate, rough or smooth. The branching of hairs is to 
be treated with caution, since the simple hairs in some species ex- 
hibit a branching tendency when supplied with abundant moisture. 
In like manner the external cells, in species with a glabrous ex- 
terior, have furnished us by their size, disposition and texture 
with valuable aid in the determination of species possessed of little 
individual character. It will not escape notice, that, of all the ex- 
ternal features which characterise the members of this genus, none 
have so much asserted their claim to recognition, or impressed us 
so strongly with their value, as an aid to classification, as the ex- 
ternal cells and their appendages. 
7. Disc. The hymenial surface, or disc of the cup is usually 
coloured, sometimes brightly, at others inconspicuously. At present 
we have failed to trace any relationship between this colouring 
and the habitat of the species. Very little reliance can be placed 
upon the colour of the disc as a distinctive feature. Carmine red 
varies sometimes to pink and even to white.* Yellows are apt to 
blanch or turn brown. Still there are some negative results which 
observation has furnished. Decided orange, such as Peziza 
aurantia , is not liable to variation, except in intensity. Verdigris- 
green, though not common, never seems to disappear or be super- 
seded. When the cups have long been dried, and are moistened 
again, the green may be seen to pervade tbe substance of such 
species as Peziza jungei'mannice. Purples are less permanent, but 
to a considerable extent possess the same property. The same 
disc will sometimes vary very considerably with age, passing from 
flesh-colour to brown, from white to cinereous, and from cinereous 
to white. The colour of the disc in Peziza is, perhaps, scarcely 
more reliable than that of the petals in flowering plants, or, at 
least, uncultivated flowering plants. 
8. Texture. This has but a narrow range in the present genus ; 
tough, coriaceous, waxy, and other textures are excluded, and rele- 
gated to other genera, so that all which remain are assumed to have 
a soft, fleshy substance, containing a large percentage of water, 
which causes the plant to shrivel and collapse in drying. Never- 
theless, some are more gelatinous than others, and become in drying 
reduced to a thin film. When a supposed species of Peziza retains 
its form and expanded disc, without shrivelling or cracking in the 
process of dessication, it may very reasonably be concluded that 
Peziza is not the genus to which it legitimately belongs. It need 
hardly be said that what is characteristic in the texture of one in- 
dividual in a species will be so of all, since we have no experience 
* A white variety of Peziza coccinea is sometimes to be found in company 
with its crimson relatives. 
