1912] CURRENT LITERATURE 187 
The plates ea photographic studies of the trunks and drawings of the 
leaves and fru 
The fae dominated by members of the Dipterocarpaceae are by far 
the most important both in extent and in volume of merchantable timber. 
The composition of these forests is a simple one from the forester’s or lumber- 
man’s standpoint, a given area seldom having more than 15 or 20 species of 
economic importance; and in the most productive of the dipterocarp forests, 
known as the lauan type, 95 per cent of the timber belongs to 6 dominant 
species. The same forest is complex from the standpoint of the botanist, 
since it contains 150~200 tree species, the greater number being too small to 
be economically important. Once within the tangled mass of lianas about 
the openings, these forests are easy to penetrate. 
n addition to an abundance of timber for general construction purposes, 
these forests produce excellent substitutes for mahogany and lignum vi vitae, 
many valuable furniture woods, and woods suitable for carving, engraving, 
and numerous other purposes. Among the other forest products are resins, 
oils, rubber, rattan, and bamboo. Lumbering methods have been largely 
primitive, but these are being replaced by more scientific ones, which promise 
to produce not only all the timber required for use upon the islands, but 
considerable quantities for export.—Gro. D. FULLER 
African sand dunes.—The vegetation of a narrow border of sand dunes 
along the shores of the Bay of Algiers has been described by DUcELLIER.” 
An annual rainfall of over 60 cm., well distributed throughout the year, with a 
maximum in November and Diecsicshies: and a minimum in July and August, 
together with a mean temperature ranging from 5° C. in January to so. 
in August, produces an evergreen vegetation with hardly a cessation of flowers 
throughout the year. Three distinct bands of vegetation correspond to three 
distinct topographic zones running parallel with the shore. First is the a8 
dune, with a vegetation characterized by the abundance of annuals and grasse 
of the usual type, belonging to such well known genera as Salsola, Cakile, 
Silene, Euphorbia, and Ammophila. Within this comes a depression termed 
“bande humide,” apparently the same as the “‘pannes”’ of European ecologists. 
Here the vegetation is a mixture of xerophytes, mesophytes, and such hydro- 
phytic forms as species of Juncus, Scirpus, Orchis, Typha, and Nerium. 
In the inland portion of the area there appear to be few dunes of any con- 
siderable size. The plants conspicuous in the fixation of the dunes are Lotus 
creticus, Seabota rutaefolia, and Pistacia Lentiscus, while the established dunes 
are occupied by Olea europea, Pinus halepensis, Phillyrea media, an nd a con- 
siderable number of shrubs and herbs mostly of decidedly xerophytic structure. 
Among the prominent families represented in the lists of species are the legumes 
4 Ducetuer L., Etude sidecases des dunes de la Baie d’Alger. Rev. 
Gén. Bot. 23: isk 321-339. 
