202 
THE SEINE, THE MEUSE, AND THE MOSELLE 
the region, its valley through the upland is not cut to a great 
depth ; it is much shallower than the valley of the Petit Morin, 
which was beheaded at a much later period, when it had become 
nearly as deep as that of the Marne itself. 
It was while studying the French maps at home that I first 
came on this almost ideal example of migrating divides and 
adjustment of streams to structures, but it was not until an ex- 
cursion abroad in 1894 that I Avas able to study it on the ground. 
I then had the gratification of confirming by direct observation, 
as far as the brief time at my disposal would allow, the expecta- 
tions formed from study at a distance. The example of the 
Marne and its side branches therefore still serves me as atypical 
case of adjustments of this kind. 
It is curious to note that another small stream, the upper 
Vaure, fiows toward the marsh of St. Gond, but instead of being 
diverted northward by the Soude to the INIarne, it is diverted 
southward l)y the Superbe, a su])seciuent branch of the Aulje. 
It seems also i)rol)able that this subsequent branch has diverted 
the Maurienne at Pleurs, and thus cut it off from the Grand 
iNIorin, whose head is, like that of the Surmelin, on the upland 
Avest of the escarinnent. 
It is manifest that the terminology here employed Avill he of 
service in simplifying the description of other examples of shift- 
ing divides and river adjustment if they ])Ossess the same sys- 
tematic features as are here so Avell exhibited. That such is the 
case I can confirm from the study of several examples near the 
escarpment of the SAvabian Alp in Wiirtemberg, Avhere the head- 
Avaters of the Xeckar are actively pushing aAvay the divide that 
separates them from the northern tributaries of the upper Dan- 
ube. Although the arrangement of i)arts is not the same as in 
the examjde near Chalons, yet the homologies of the'tAVO regions 
can l>e clearly made out. The same may be said of the rivers of 
central England, Avhich are as a rule Avell adjusted to the val- 
leys betAveen the uplands of the oolite and the chalk. 
(7b be continued.) 
