210 GEOGRAPHICAL STATISTICS OF THE EUROPEAN FLORA. 
true R. tripartitus will be found not unfrequent in the western counties, 
Mr. Cunnack has collected it near the Lizard. Search should also be 
made in that part of England for R. ololeucos, which diffeed in having 
the petals wholly white, and for R. ¢ripartitus, var. ne a 
curious form quite without floating leaves. —Henry Tr1 
Extracts and Abstracts. 
GEOGRAPHICAL STATISTICS OF THE EXTRA-BRITISH 
UROPEAN FLORA. 
By Tuomas ComsBeEr. 
Seeeecrts from p. 185.) 
Large genera, on the contrary, have a higher degree of dispersion 
than small, archoaiti the daffersnke between them is not so great as in 
British plants. Ranking those genera as “large”? whose total number 
of mig de soags exceeds 100, we have this comparison :— 
Bet oe 
1933 pees to ss large oh 2°68 
maller 2°61 
aie ora yee to ne oe differing from the 
typical form, was found amongst British plants to be accom panied by 
an increased specific range. i omparison, which 
species have been ranked as variable that comprise forms sufficiently 
divergent from the type to be considered by some authors distinct 
species :— 
Species, bg tg 
1528 variable . i i i e : 3°69 
5089 not variable. : = eek 
now ehasked, so far as the mate- 
lf to our notice when we were considering the British 
namely, Alpine plants. Accepting Mr. Darwin’s theory of 4 
I have termed Arctic-alpine plants in the extreme n the 
mo of Southern Eu nd their absence from the inter- 
mediate low grounds, the question arises, Why are not Alpine plants 
also — in the Arctic re ions ? Does it arise fi heir more 
recent origin as species : from their not having come i 
until = e de northward of the Arctic-alpine ingot 
_ Special 
101 Arctic-alpine : 
04 Alpine’ id wey a + de7e 
