4 
ON UNDERGKOUND FUNGI. 
including the large tribe of mushrooms, and their numerous close allies 
for which we have no general popular name, though most of us know 
that of the puffballs, and our smell informs us too unpleasantly of the 
presence or neighbourhood of the stinkhorns, a few, however, of which, 
especially of exotic species, are extremely beautiful objects. As regards 
the other branch we have the cup-shaped Fungi, known under the 
name of Pezizas, some of which attract notice by their splendid 
colour. 
There is a third group to which we shall have to advert pre¬ 
sently. As, however, the true truffles of commerce are the objects of 
most importance in an economical point of view, I shall advert to 
these first. 
The common Truffle, whether under that name we include 
the French Truffle* (Tuber melanoaporuiii), the black-seeded Truffle, or 
our own most abundant species Tuber cButiinim, the summer Truffle, 
presents when divided vertically a number of pallid veins which 
communicate with the warty surface of a dark brown or black 
tint, and consist of branched threads, which answer to the hymenium 
(fructifying surface) of the cup-fungi, as they give rise to the fertile 
threads whicTi are terminated by the seed-sacs. A common lens is 
sufficient to indicate their presence, where they appear as dark specks. 
The further investigation requires a compound microscope, and few 
objects are more interesting than the enclosed sporidia, of some of the 
more marked of which I have submitted figures to the meeting, Thev 
are in general of a comparatively large size, and their external surface 
is variously spinulose, warty, or reticulated, often to an extent which 
does not take place in more aerial Fungi. In a few cases, how¬ 
ever, as in Balsamia, they are smaller and quite even. Very little is 
known about the impregnation of Fungi, but in the true Truffles, as in 
some species of the cup-fungi and the water-fungi, which are the 
destruction of fish, and especially of young salmon, certain threads 
swell at the tips and curl round the sacs, to which they impart the 
male element, the whole process in Truffles being completed beneath 
the surface of the earth. Spermatozoids or spermatia have not been 
discovered in these Fungi. 
Several species have been found in this country, each of which is 
distinguished by its own peculiar odour ; but most of these are so small 
that they are at once thrown aside by the collectors. The odour of 
Tuber melanosporum is so penetrating that it cannot escape the prying 
nose of the exciseman or douanier, however cunningly it may be 
concealed. 
There is, however, a distinct genus Choiromyces, known amongst 
other peculiarities by its pale colour and even surface and globose 
sporidia, which is esculent, though far inferior to the summer Truffle. 
The species sometimes grow to a large size, and are met with unexpec- 
* We believe that the truffle collectors at Audley End call young Tuber 
('eativum before the seed-sacs are formed by that name. 
