246 NOTES AND COMMENTS [ocroBER 
land surface. “There are several ways in which these plants tend to 
diminish the water-space and to increase the dry land. By their own 
decay they form vast masses of vegetable soil in shallow waters and on 
water margins; by occupying running streams they moderate the flow 
of the current and give it time to deposit its silt; by their creeping 
rhizomes and spreading roots they fix the bed of a stream and prevent 
it being scoured and deepened by floods, and again in times of flood 
they serve as a sieve or strainer, arresting all floating and much 
suspended solid matter.” This is indeed a familiar theme, but the 
author discusses it with freshness and with appreciation of its dramatic 
interest. . . . “Inch by inch, as the result of this accumulation and 
decay, the land creeps in upon the mere; more and more solid grows 
the edge; the aqueous plants retreat from the now shallow margin, the 
terrestrial plants advance, finding firmer footing; the sedges and reeds 
crowd on their floating neighbours which need space, and cannot endure 
the shade; these, too, press forward, and the open water grows less and 
less ; it is invested on every side, and it is plain that its complete 
subjugation is now only a matter of time.” It would be of interest to 
procure some actual measurements of the amount and rate of land- 
winning, and to study in minute detail the elimination which proceeds 
as the mere is closed up. 
The Progress of a Great Work. 
? 
EIGHT parts are now available of “Das Tierreich”—the “Systema 
Naturae” up to date—which is being issued to an ungrateful world by 
the German Zoological Society through the medium of R. Friedlander 
and Son in Berlin. The magnum opus will give a classification and 
diagnosis of all living animals, and the issue of eight parts in a 
relatively short period permits us to hope that we shall live to see it 
completed. The general editor is Professor Franz Eilhard Schulze, and 
there are many sub-editors. Of the collaborateurs whose names are 
published the majority are German, but most of the European countries 
are represented by well-known workers. Britain is represented by 
Mr. W. E. Hoyle of Manchester, the Hon. L. Rothschild, Drs. 
Hartert and Jordan of Tring, Mr. A. D. Michael, Mr. W. R. Ogilvie 
Grant, and Dr. Bowdler Sharpe in London, the Rev. T. R. R. Stebbing 
in Tunbridge Wells, and Prof. D’Arcy W. Thompson in Dundee. The 
part before us is by Dr. A. Labbé, and deals with the Sporozoa; it 
occupies 180 pages, has 196 figures, and costs 8°80 marks to sub- 
scribers, and about a third more if purchased singly. The other parts 
published deal with various families of birds and mites, with a division 
of copepods, and with scorpions and Pedipalpi. It is not necessary to 
point out the magnitude of the boon which this great work will confer 
on systematic zoology, but perhaps it is permissible to urge individual 
