220 NEW PUBLICATIONS. 
then it has not shown itself in several of these places, while in others 
it occurs only in isolated patches. In the year 1862 it sprang up wn- 
expectedly and abundantly in the tanks of the Botanic Gardens at 
Dresden, in which the Victoria regia is cultivated. Another pheno- 
menon may be mentioned for the benefit of young algologists. At 
different seasons of the year different Algæ are found in one and the 
same locality. For instance, in May and June species of Ulothria may 
found on the floating timber of the Elbe ; while in July and August 
Cladophora glomerata is common, and no trace of Ulothriz remains.” 
L Ardenne.. Par Francois Crepin. | 8vo, pp. 68. Brussels: Gustave 
ayolez. 1863. 
The Belgians, amongst whom, a few years ago, local botany was but 
little cultivated, are now working hard at the study of their indigenous 
vegetation and its distribution. In 1859, M. Crepin, of Rochefort, who 
has since been chosen Professor at the State School of Horticulture at 
Ghent, published the first fascicle of his * Critical Notes upon Belgian 
Plants,’ and this has since been followed by two other fascicles, all 
three containing. valuable observations upon critical species, and the 
report of experiments of cultivation which bear forcibly upon the 
question of how far some of the proposed species which have been 
obtained by the dismemberment of the old specific types are really 
distinct. In 1860 appeared the * Manuel de la Flore Belgique’ of 
the same author, an elementary handbook of the Belgian flora, with 
analyses of the genera and species, and short descriptions and notes of 
station. In 1861 were published a Flora of the province of Brabant, 
by Professor Van Heurck, of Antwerp, and M. Wesmael, of Vilvorde, . 
and the first part of a Flora of the province of Antwerp, by MM. Van 
Heurck and Beucker, the first in French and the latter in Dutch. A 
Belgian Botanical Society has been formed within the last two y eno 
to unite together the workers and systematize their labours, and under | 
its auspices meetings are held and excursions organized. Professor 
Van Heurck published last year a fasciculus of dried specimens of fifty 
of the more interesting plants of the country, and these he proposes 
to continue annually. M. Crepin intends to issue, in the course of. : 
1863, a ‘Revue de la Flore Belgique, with extended descriptions and | 
geographical notes, to reach altogether about 450 pages. In 1862 he 
