Mas see. — A Monograph of the Geoglosseae. 235 
from the apex, we get the pileate form of Leotia ; and in some 
of the higher forms of Mitrula this condition sometimes 
occurs, thus illustrating the so-called transition phases between 
those groups of species possessing several features in common, 
which we call genera. 
The spores in Spathularia are of the Geoglossum type, but 
colourless ; whilst the ascigerous portion is more sharply differ- 
entiated from the stem than in Geoglossum , and is also 
frequently laterally compressed or spathula-shaped, more 
especially in the species on which the genus is founded, 
whence the generic name. Finally, Vibrissea has the Spathu- 
laria type and colour of spore, but the ascigerous portion 
is pileate, thus differing from Spathularia in the same manner 
that Leotia differs from Mitrula. 
From the above remarks it may possibly be inferred that 
genera in the Fungi are somewhat shadowy, but in reality 
not more so than in other branches of the Vegetable Kingdom, 
and perhaps our knowledge of true affinities becomes more 
exact in proportion as our belief in genera as entities 
becomes less. 
The transition from the Geoglosseae to other families of 
the Discomycetes is gradual ; the line between species of 
Leotia and Ombrophila belonging to the Bulgarieae is purely 
a matter of personal opinion ; the same may be said of the 
species of Vibrissea and Gorgoniceps , the latter belonging to 
the Pezizeae. Leotia shades into Verpa belonging to the 
Helvelleae on the one hand, and on the other into Helotium, 
belonging to the Pezizeae. Finally, Helvella of the Hel- 
velleae leads very gradually into Geopyxis , belonging to the 
Pezizeae. 
The diagram on p. 236 shows the evolution of the genera 
of the Geoglosseae from Geoglossum ; also the origin of the 
Helvelleae, Bulgarieae, and Pezizeae from the Geoglosseae. 
Distribution. 
In dealing with problems relating to distribution, mere 
numbers are apt to mislead, owing to our comparatively 
