74 BOTANICAL GAZETTE [JANUARY 
piration reaches its minimum just before the cambium resumes its activity: 
The paper includes a rather extended inspection of the literature—RAYMOND 
H. Ponp . 
Ecology of woodland plants—WoopHEAD"3 has investigated the woodland 
plants near Huddersfield, England, and has made an important addition to the 
ecological literature that is rapidly developing in Great Britain. The subject 
is still new enough, however, for the author to preface his paper by a brief account 
of the study of ecology in Britain. The first section of the paper is physio- 
graphic, dealing with the woodland vegetation maps of the various areas under 
consideration. The second section is anatomical, discussing the effect of envi- 
ronment on structure. Under the head of dominant species, there are described 
the leaf, petiole, and rhizome of Pteris aquilina; the leaf, absciss-layer, and 
elongated bulbs of Scilla jestalis; and the leaves of Deschampsia flexuosa, Holcus 
mollis, and Vaccinium Myrtillus. Under the head of secondary species, the 
leaves of va eracleum S phondylium, Lamium Galeobdolon, and Mercurialis perennis 
are described. The vegetation of the Huddersfield district is naturally divided 
into ius parallel zones: (1) the moss moor (1700-1000 feet altitude), the most 
exposed zone, dominated by Eriophorum vaginatum or on drier ridges by 
Vaccinium Myrtillus; (2) the millstone-grit plateau (1000-500 feet), with oak 
as the dominant tree, associated with birch and pine; (3) the Coal-measure 
area (500-200 feet), with deep and well-watered humus soil.—J. M. C. 
Phycophaein.—Tswert finds'4 that phycophaein does not exist as such 
in the living body of the brown algae. He does find, however, that a colorless 
chromogen, soluble in water but insoluble in alcohol, is present. An extract 
made with distilled water contains this chromogen, but owing to its neutral 
reaction the solution becomes colored very slowly. Extraction with an alkaline 
solvent, such as ordinary tap water, gives a yellow solution, rapidly becoming 
brown by oxidation. Decoloration occurs when the reaction is made aci 
Extracts of the thallus with 50 to 80 per cent. alcohol remain colorless. This 
work, done in RertNKe’s laboratory, sustains his hypothesis of the post-mortem 
origin of phycophaein and refutes the generally accepted notion that it is a 
genuine pigment of the chromatophore. The remainder of the paper outlines 
the author’s method for isolating the several pigments present in the se 
phore. The following are soluble in petroleum ether containing 10 per 
alcohol; carotin, chlorophyllin a, fucoxanthin, and fucoxanthophyl. Choi 
y is not soluble in this reagent, but is soluble in alcohol and ether. The natural 
color of the brown algae results from a mixture of these pigments in the pee, 
matophore.—Raymonp H. Ponp 
13 WOODHEAD, T. W., Ecology of woodland pings in the neighborhood of Hud- 
dersfield. Jour. Linn. Soc. Bot. 37: 333-406. figs. 70, 1906. 
%4TsweEtt, M., Zur Kenntnis der eas ee Ber. Deutsch. Bot. 
Gesells. 24: 235-244. 1906. 
