506 STUDIES FOR STUDENTS 
surface. It is only where tidal channels of this kind are main- 
tained, breaking across the embankment of dunes, that the shore 
line shows significant irregularity by bending somewhat seaward. 
The surface of the plain is in a very young stage of its life 
history, but its margin, beaten upon by a stormy sea, must be 
regarded as more maturely developed. It is just such a flat coast 
as should have normally been provided with an off-shore bar in 
the earlier stages of sea attack; but if such a bar ever existed 
here, it has now been pushed in against and upon the land, the 
sea bottom deing deepened at the same time, until at present the 
waves roll in and cut the margin of the plain itself. The pro- 
longation of the slope of the plain does not now coincide with 
the sea floor; the latter is distinctly below the former (Reclus, 
_La France, 103). This satisfactorily illustrates a case of the 
more rapid advance into the cycle of geographical development 
under the strong attack of the marginal waves than under the 
weak action of the superficial drainage; but this is not a con- 
stant relation. 
The features here illustrated are of a simple kind; but they 
are of value in preparing the way for a clear understanding of 
more complicated examples. 
GERMANY. 
KARTE DES DEUTSCHEN REICHES: Scale, I—100,000, with hill 
shading in hachures; sheets 11x13 inches; printed in black, 
except waters in blue. Altitudes of various points in meters. 
Sale Agent: R. Eisenschmidt,-Neustadtische Kirchstr. 4/5, 
Berlin, N. W., Germany. Price of sheets, 1.50 marks. 
DAE VISPULA AND f2HE  NEDZE. 
SINEGUS AO DA BD, DAO. DE, BEM, DES. DEA. 
The Vistula has a sharp elbow or turn in its course from 
northwest to about north close to Bromberg, some ninety miles 
south of its mouth. In prolongation of its upper course, but 
gradually curving to the westward, is a broad-floored valley now 
occupied by an insignificant stream, the Netze, which comes 
