A SUMMER IN GREENLAND 
59 
plants presents interesting problems in relation not only to tbe 
efficiency of plants as travellers, but to the position of tlie places 
from which they originally spread”; in this connexion Cassiope 
tetragona and Fhyllodoce ccerulea are considered in detail. 
A word must be said in praise of the illustrations from photo¬ 
graphs, which as a whole are excellent; those groups of plants, 
however, are on too small a scale, and the one supposed to represent 
Fyrola grcindijlora might well have been omitted. 
Researches on Fungi , Yol. II. By A. H. Reginald Buller, 
B.Sc.(LoikL), etc.; Professor of Botany in the University of, 
Manitoba. Longmans, London, 1922. Pp. 460, with 157 
figures in the text. Price 25s. net. 
This work of absorbing interest is indispensable to the student 
of our larger fungi. It embodies the results obtained by years of 
painstaking and laborious investigation. Professor Buller confirms 
Fayod’s discovery of the excretion of a drop of water at the hilum 
end of a spore immediately before its discharge, and finds that the 
drop is always present there for a few seconds in all the Hymeno- 
mycetye examined by him, and considers it is essential for the violent 
projection of the spore from the sterigma. The hymenium of the 
llymenomycetse consists of basidia, paraphyses, and cystidia. The 
basidia are present from the very first in great numbers and come to 
maturity in a series of successive generations, but each individual 
basidium only produces one generation of spores, and after the pro¬ 
jection of the spores the sterigmata shortly afterwards collapse on 
the exhausted basidium. The paraphyses are distinct elements of the 
hymenium from the very first, and their function is to support and 
nourish the other members. The cystidia, like paraphyses, are sterile 
elements, and differ from these in their larger size, peculiar form, 
and smaller number, and are present in some species and not in others. 
All these elements of the hymenium are most beautifully and accu¬ 
rately depicted in a series of camera lucida drawings, photographs, 
and diagrams at the various and successive stages of their develop¬ 
ment. 
We consider Professor Buller wrongly unites Dacromyces deli- 
quescens I)uby and _D. stillatus Nees as representing the two con¬ 
ditions of one and the same species, because the latter differs from the 
former in its larger basidiospores and basidia, and the oidial form 
is well known to all systematists. The monstrous fruit-bodies of 
Folyporus rufescens Fr. (now more generally known as Fcedalea 
biennis (Bull.) Quel.) arise from failure to respond to geotropic 
stimuli, but all other authors consider them to be the well-known 
Ftychogaster or conidial form of this species. 
The systematist will bo greatly interested in the description and 
illustrations of the curious and abnormal forms of Marctsmius oreades 
that arise when this plant is cultivated for four years from spawn on 
a soil-covered bed of manure. He will also read, perhaps witli some 
