398 
C. E. Moss. 
THE INTERNATIONAL PHYTOGEOGRAPHICAL 
EXCURSION IN THE BRITISH ISLES. 
XII.— Remarks on the Characters and Nomenclature of 
some Critical Plants noticed on the Excursion. 
By C. E. Moss. 
YMPHAZA alba var. occidentalis Ostenfeld in New Phyt. xi, 
-* ™ 116 (1912). Mr. Druce still prefers the generic name Castalia 
which involves the use of Nymphcca for Nuphar; but I do not 
doubt that most botanists will be pleased to find that it is in strict 
accordance with the international rules of nomenclature to retain 
Nymphcca and Nuphar in their more familiar meanings (cf. Briquet, 
Prodr. FI. Cors., 577 (1911), and Rendle in ’Pfourn.Bot., 277 (1911) ). 
It is interesting to note the two views which the members of 
the excursion show a tendency to adopt with regard to this and 
other new forms encountered on the excursion. On the one hand, 
some members are inclined to regard them as characteristic of, and 
related to, the insular climate of western Europe in general; and 
this view is crystallised in the name which Dr. Ostenfeld has 
bestowed upon the new water-lily. On the other hand, some other 
members suggest more or less definitely that they are instances of 
endemism in a continental island. It is too early to pronounce 
any verdict on the merits of the two hypotheses; and indeed it may 
well be that each will prove to be deserving of a measure of support. 
I hope, however, that the theory of endemism will not be hastily 
adopted, even as a working hypothesis. Before the new forms 
receive new names, it is essential that they should be compared 
with similar and closely allied plants known from the mainland of 
Europe. This, of course, Dr. Ostenfeld has done; but it seems to 
me there is a real danger in the theory of endemism as now being 
put forward—a danger of new, or presumably new, British forms 
receiving new names which will be found later to be mere synonyms 
of older and well-known names in some Europaean countries. Even 
if forms have arisen independently in the British Isles since the 
