No. 384.] REVIEWS OF RECENT LITERATURE. 961 
is planning another voyage to the Malay Archipelago for the express 
purpose of studying the question of fructification, and we may hope 
that it then will be settled. 
A New Volume of De Toni’s Sylloge. — The Sy/oge Algarum, 
by J. B. De Toni, begun in 1889, has now reached Vol. iv, of which 
the first section is just issued. This volume will contain the Floridex, 
arranged on the Schmitz-Hauptfleisch system, as given in Engler and 
Prantl. A work like the Sy/oge, giving a more or less complete 
diagnosis, in its appropriate systematic place, of every published 
species of alga, with references not only to the original publication 
but also to all the important works in which the species is mentioned, 
Saves an immense amount of time otherwise needed in looking over 
the very scattered literature of the algæ. It should not be forgotten, 
however, that the Sy//oge is not intended to be a critical revision, and 
any attempt to determine species of a large or difficult genus by it 
would give very uncertain results. In a work of this extent, so largely 
references, some omissions and errors are probably unavoidable, and 
it is hardly safe to copy any reference without verification ; but per- 
haps this is the only safe rule, even with the most accurate works. 
Studies on Phytoplankton.— The study of the plankton, the 
minute animal and vegetable life distributed through the sea, at all 
depths, has attracted much interest recently and seems likely to have 
important practical results. Recent publications, by Cleve? and 
others, indicate that the pelagic flora and fauna of each great region 
has a character of its own, and that by observing the changing char- 
acter at any given locality it may be possible to ascertain from what 
oceanic region the currents are flowing at the time. At certain points 
on the coast of Sweden, for instance, the water at one time of the 
year shows the characteristics of the southern part of the German 
ocean ; at another part of the year, the characters of the Arctic and 
North Atlantic. That a more thorough knowledge of the laws gov- 
erning these changes may give some indication of the causes of the 
migrations of food fishes seems not improbable ; the practical value 
of such ee would be very great. 
i, J. B. Sylloge Algarum hucusque cognitarum, vol. iv, Floridex, 
Sectio 1, eae I-Ix. Patavii, 1897. 
2 Cleve, P. T. A Treatise on the Phytoplankton of the Atlantic and its Tribu- 
taries, and on the Periodical Changes of the Plankton of — Upsala, 1897. 
Cleve, P. T. Karaktiaristik af Atlantiska Ocean vatten pa grund af dess 
mikroorganismer. Oecefvers. K. Vetensk. Akad. Pokaat. Stockholm, 1897. 
