Phytogeographical Excursion in the British Isles. 115 
montanum is British, var. vulgave is more eastern and northern 
(Denmark and South Scandinavia). In other instances the British 
Isles have the same variety or species as Scandinavia, e.g., AlcJii- 
milla acutidens and Erigeron borealis. Such is the case with regard 
to the more northern forms, which must have come to the British 
Isles soon after the Ice-age and which are now confined to their 
northern and “ alpine ” regions, while they also occur in the Scandi¬ 
navian mountains. In yet other instances the British Isles harbour 
more than one race, e.g., Scirpus ccespitosus var. austriacus and var. 
germanicus, and Rumex acetosella var. acetoselloides and var. 
angiocarpus, which have different geographical distributions 
elsewhere. 
These examples may bring out what I mean, and I think com¬ 
parisons on these lines must give us a better understanding of the 
paths of postglacial immigration and of various problems of floristic 
phytogeography relating to those countries which are supposed to 
have been wholly covered by the land-ice and are consequently 
inhabited by a flora of postglacial origin. 
In the following pages I am publishing some results of the 
examination of my collections, and 1 hope they may be of interest 
to British floristic phytogeographers. I know they are very incom¬ 
plete in many respects, and if they stimulate further studies in this 
direction, they will have done their duty. Undoubtedly much that 
is here written will have to be corrected or abandoned. 
I have only dealt with some scattered genera, as my friend, 
Mr. G. C. Druce, has already published a full report on the floristic 
resuts, 1 and he is, of course, much more competent to tell what is 
of interest in the British flora, than I a foreigner. But, at least, 
these notes may serve as a further proof that the brilliant excur¬ 
sion has had results in the floristic direction. 
The sequence in the natural orders is that adopted in the 
British floras, e.g., Babington’s Manual.” 
Ranunculace/E. 
Ranunculus, Sect. Batrachinin S. F. Gray. In Denmark and 
Scandinavia the authors mostly follow the excellent monograph of 
the species of water-crowfoot, published by my late friend O. 
Gelert (Botanisk Tidsskrift, vol. 19, 1894, Danish with French 
resume), according to whom the number of species is rather 
restricted and each species is very variable. Using this monograph 
as a standard, I have noticed from our excursion (besides R. heder- 
aceus L), two species, viz., R. paucistamineus Tausch var. Drouetii 
1 New Phyt., Vol. X, pp. 306—328 1911. 
