Algae. 
487 
Fritsch, F. E., The Röle of Algal Growth in the Coloniza- 
tion of new ground and in the determination of Scenery. 
(Geographical Journal, p. 531 — 548; 1 fig. and 2 plates. Nov. 1907.) 
In temperate countries the green coating on tree-trunks, and 
the various hues imparted to wet rocks by Algae are not without 
their effect on scenery. In Ceylon, where the author has made his 
observations, and in other parts of the tropics, the sub-aerial algal 
covering is much more developed, especially in the regions with a 
high rainfall. Dark coatings of Cyanophyceae prevail rather than 
green Algae, and this is traced to the effects of plentiful moisture, 
high temperature and intense illumination. The influence of periods 
of dessication is also observable; species with tough sheaths ( Lyng - 
bya, etc.) were observed to prevail in the lojvlands of Ceylon, 
whereas mucilaginous and slimy species (. Nostoc, Gloeocapsa , etc.) 
were more abundant in the humid uplands. As regards mode of 
growth, the author distinguishes four types which succeed one 
another in colonizing new ground: a) adhesive growth is shown by 
those forms which grow as a film on the substratum; b) the tangled 
type has filaments interwoven into a loose feit enclosing air which 
is difficult to dislodge even when soaked with water; c) the tufted 
growth is more suited for absorbing water-vapour from the air, and 
arises from the tangled form by emergent threads becoming sur- 
rounded by other filaments to form tufts which together give the 
algal growth a velvet-like appearence. d) Stratified growth follows 
when the tufts become arranged in definite tiers one above another. 
This succession was observed in Ceylon; it can also be observed 
in moist hot houses, as shown by a series of photographs taken at 
Kew. Observations on the colonization of rock-surfaces and walls 
are described to illustrate the succession from adhesive growth on- 
wards; the process may under favourable conditions be rapid as in 
one case where a newly whitewashed wall was covered by a blue- 
green film in three weeks, and began to show the tufted growth in 
three months. 
Examples of how aquatic Algae prepare the soil for higher 
Vegetation are given from observations on a salt-marsh in Brit¬ 
tany. The soil is overgrown by filaments of Rhizoclonium and 
Lyngbya, which assist in retaining the tide-borne silt, and by their 
decay add to the humus-content of the evil-smelling sandy mud 
which forms the substratum for a luxuriant salt-marsh Vegetation. 
On a Pes-caprae sand-strand in Ceylon, a Nostoc was also observed 
in large quantities. The paper is anaotated with references to 
existing literature, and thus provides a useful summary on this 
aspect of algal activity. W. G. Smith. 
Yendo, K., The Fucaceae of Japan. (Journ. of the College of Sc., 
Imp. Univ., Tokyo, Japan, Vol. XXI, Article 12. 174 pp. with 18 
plates, 1907.) 
After short introductory remarks the author treats on the 
“Distribution of Fucaceous Algae on the Coast of Japan” in which 
he enumerates Sargassum setaceum, pinnatifidum, tosaense, kashiwa- 
jimanum, kushimatense, Elicifolium var. duplicatum , cristaefoliinn, 
graminaefolium, sagamianum, nipponicum as the plants peculiar to 
the Pacific side and Sargassum fulvellum, confusum, and f. validinn, 
Thunbergii f. nipponica, Miyabei, Cystophyllum caespitosum. Cocco- 
phova Langsdorfi , Coc. Imperata as peculiar to the Japanese Sea side. 
