ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
91 
Rosellinia Pepo, an Ascomycete Injurious to Cacao in Trinidad, 
West Indies. — W. Nowell {Bull. Dept. Agric. Trinidad and Tobago , 
1920, 18, 178-99, 5 figs.). An account is given of several diseases of 
plants due to some species of Rosellinia. R. Pepo attacks cacao, and 
in most cases passes to the cacao from the roots of dead or dying shade 
trees. It also attacks Citrus aur antifolia, while R. bunodes causes a 
disease of coffee. The fungus penetrates the bark and wood, and may 
quickly cause the destruction of the tree by destroying the bark round 
the collar. Remedies are suggested. A. L. S. 
Presence of Oak Oidium in Brazil. — A. Puttemans {Bull. Soc. 
Path. Veg. France , 1920, 7, 37-40 ; see also Bull. Agric. Intell. and PL 
Diseases Rome , 1920, 11, 1061-2). The Oidium wa§ first observed in 
Sao Paulo in 1912, on trees of Quercus pedunculata of about fifteen 
years of age. The fungus itself was parasitized hj'-Cincinno bolus Cesatii. 
The disease had been discovered six years previously in Europe, and the 
mode of its introduction into Brazil is discussed. The author thinks it 
may have passed by way of Madeira, where it was reported in 1908. 
A. L. S. 
Investigation of some Tomato Diseases. — F. T. Brooks and 
Gl. O. Searle {Trans. Brit. My col. Soc., 1921, 7, 173-97). The 
authors have been studying the various fungi that do damage to 
tomatoes. A list of the forms with which they dealt and the cultural 
and other experiments are described. Several of the forms under 
examination were identical with those described from American States. 
The synonymy of several species has been cleared up, and our know- 
ledge of the parasitic fungi placed on a clear basis. A*. L. S. 
Lichens. 
Methodical bases of Modern Plant Sociology. — G-. Einar du 
Rietz ( Upsala , 1921 ; Wien , Adolf Holzhausen , 1921, 272 pp., 38 tables, 
22 figs.). The author has given a historical account of the study, 
Ecology (Plant Sociology), in the different schools of Europe and America, 
reviewing all the literature and the different systems. He gives results 
of his own examination of various localities in Sweden, and describes his 
methods and results. Particular attention is paid to Lichen associations 
either in conjunction with other vegetation such as Deschampsia 
flexuosa — Cladonia rangiferina-silvatica, etc., or as almost purely lichen 
associations the names of which indicate the dominant species as 
“ constant,” and these he lists in full. The Parmelia omphalodes 
association he found included two mosses and fifty-nine other lichens, 
several of them constant variants. Another prominent association, 
which occupies dry mountain ridges, he designates the Lecanora deusta 
ass. ; with it as a constant is Lecidea rivulosa. Later he refers to a 
“ Lecidea rivulosa association,” with these are associated many crustaceous 
lichens which cover large areas. “ Lecanora quartzina association ” 
occupies a zone of sea-coast rocks exposed to storms. The author gives 
a 'critical resume of the methods and aims of plant sociologists and 
appends a long and more or less complete bibliography. 
A. Lorrain Smith. 
