Fungi. 
39 1 
The author does not state, however, that at least one-third of these 
are not indigenous to the county. 
On the whole, the Flora of Cornwall is a straightforward and 
useful account of the plants of Cornwall ; and the hook, although 
expensive, will he extremely useful to a large number of people who 
wish to herborize in one of the most interesting parts of Britain. 
C.E.M. 
FUNGI. 
“Researches on Fungi/’ by A. H. Reginald Buller, Professor 
of Botany at the University of Manitoba, pp. XI. + 287. Longmans, 
Green & Co., London, 1909. Price, 12/6 net. 
I N a subsidiary title the author explains that the present volume 
comprises “an account of the production, liberation, and dis¬ 
persion of the spores of Hymenomycetes treated botanically and 
physically, also some observations upon the discharge and dis¬ 
persion of the spores of Ascomycetes and of Pilobolus.'" By far the 
greater part of the book is concerned with the sporophores of 
Hymenomycetes which are primarily considered from the point of 
view of spore discharge. The author’s own researches along these 
lines are well known. This book collects together much of the 
previous work done by Professor Buller and a considerable 
quantity of hitherto unpublished material. Its publication indicates 
a distinct advance in our knowledge of the higher fungi. 
In the opening chapters of the hook the author discusses the 
efficiency of the sporophores of the Hymenomycetes as organs 
for the formation and liberation of enormous quantities of spores. 
He makes some interesting calculations to show what a large 
relative increase of hymenial area is given by the production of 
gill plates in the Agaricineae and of spores in the Polyporea?. He 
points out also the necessity for stability of the fructifications of 
these groups if spore-discharge is to be effected efficiently, for, 
were the pileus of a mushroom e.g., allowed to sway to and fro, very 
few of the spores would be able to fall free from the gill plates. 
One of the most instructive parts of the book is undoubtedly 
that dealing with the correlations made by Professor Buller 
between the reactions of the fruit bodies of the Hymenomycetes to 
external stimuli such as light and gravity on the one hand and the 
general structure and habitats of these fungi on the other. Thus 
the development of the fruit bodies of Lentinus lepideus is affected 
both by light and by gravity, while the fructifications of the common 
mushroom ( Psnlliota campestris) react only to gravity. The former 
fungus grows on wood and its orientation to the substratum is 
indefinite, so that heliotropic curvature of the stipe would be of 
obvious advantage. On the other hand the mushroom in nature 
grows on the ground, the surface of which is generally horizontal 
over a limited area; thus heliotropic reaction in this case is 
unnecessary. The author correlates also the heliotropism exhibited 
by many coprophilous fungi (e.g., Coprinus , Pilobolus) with the 
irregular surface of the substratum on which they grow. 
The spore cloud of Polyporus squniuosus is then described, a 
phenomenon which, it may be said in passing, is extremely striking 
to one viewing it for the first time, Similar spore clouds have 
