ON UNDERGROUND FUNGI 
5 
tedly in the most unlikely spots, but occur occasionally in great pro¬ 
fusion, principally in avenues of oaks. We are not aware, however, that 
they ever appear in our markets, and when fresh they are rather acrid. 
Either the same genus, or one closely allied, produces in Africa and 
near Damascus abundance of esculent Fungi, of which I have received a 
large bag of dried specimens, which proved when cooked perfectly insipid. 
They occur principally about the roots of several species of Cistus, 
and are found again in the Canaries. They are quite worthless as far 
as aroma is concerned. The Ghoiromyces, or white Truffles, have long 
been known in this country, and are figured by Sowerby. A small 
Truffle, belonging to the genus Balsamia, distinguished by its small, 
oblong, smooth sporidia, is often rooted up by squirrels under beech 
trees, the odour, as the name implies, betraying its presence. 
One of the most curious and instructive genera, as throwing much 
light on the structure of Truffles, is that of Genea, of which we have 
more than one species in this country. It is, in fact, a Truffle 
unravelled, as it were, or turned inside out, so as to expose every one 
of the veins, so that each has a distinct peridium, the whole having one 
general aperture, instead of all the veins being enclosed within a 
single crust. It is foreshadowed, perhaps, by those species of Peziza 
which are more or less subterraneous in their mode of growth, as 
P. geaster, &c. It is, however, to be remembered that the sporidia 
have no longer the same hyaline appearance, while the structure of 
the outer coat resembles that of Tuber. In the genus SpJiarosovm, 
there is no peridium, and the structure is as near that of Peziza as is 
conceivable, the hymenium being merely undulated or tuberculated. I 
might advert to other genera of which we have examples, and of some 
of which no British species has as yet been discovered, especially that 
of Picoa which will some day reward researches among bushes of 
Juniper. Hydnotnja, like Sphcsrosoma, is entirely without peridium. 
The genus Elaphornyces approaches some of the Puffballs, but has asci, 
and the sporidia, which are perfectly globose, have more than the two 
usual integuments. The genus Scleroderma, however, which is a true 
Puffball, is sometimes quite hypogaeous in its mode of growth, 
especially where the soil is sandy ; and in some parts of Belgium or 
the United Provinces, where it is very abundant, it is used when 
young as a substitute for Truffles, of which it is a sorry representative. 
It is said it is used especially for the Strasburg terrines. It will, 
however, be more interesting to proceed to others which are 
more distantly related in structure to the Puffballs, but in 
which the veins are not resolved into a mass of threads mixed with 
the dusty spores. One of these, belonging to the genus Melanogaster, is 
well known at Bath as the red Truffle, but though so far culinary as 
to be employed to give a dark colour to the sauce of a salmi, it is 
quite free from any pleasant aroma, and if largely used it is very 
doubtful whether it is quite wholesome. When fresh, the odour is 
powerful enough, and in an allied species which occurs sometimes in 
company with the summer Truffle, the smell is quite overpowering, 
