TIIK lUJlTISir AND SWISS ALPINE FLORAS. 
47 
These numbers are derived from the " London Catalogue of British 
Plants" (ninth edition, 1895), and from GremU's "Swiss Flora" 
(translated by Paitson, 1889). In these two works a large number of 
plants are given under dillerent names, and in addition to this there has 
been the usual dilliculty in discriminating between species, subspecies, 
and varieties. For, as is well known, the species of one author are 
frequently regarded as mere varieties by another. The exact number of 
genera and species recorded in these two works are therefore untrust- 
worthy as the basis of a comparative study. Some sort of standard 
is required. The standard which I have adopted here is that of the 
Index Kewensis, to which I have made constant reference ; only those 
species which are stated in Index Kewensis to be real species, and not 
varieties, having been counted. I would, however, specially emphasise 
the fact that, while these figures have been drawn up with much care, they 
are not to be regarded as exactly, but only as approximately, correct. 
These figures present several points of interest. In the first place we 
see that the /a?^i///f' 6' represented in both the floras under consideration 
are practically identical. There are only three British families not 
represented in Switzerland, and these contain but four species. The 
orders are : FrankeniacetT, Myricacea?, and EriocaulonCfTe. The genus 
Frankenia, the Sea Heaths, are essentially maritime plants, and are 
represented in Britain by two species, one of which is, however, of doubt- 
ful occurrence. The other species are Myrica Gale, L. in Europe con- 
fined to the northern and north-western districts, and Eriocaulon 
septangulare, With., a North American plant occurring in Scotland and 
Ireland but nowhere else in Europe. 
In the Swiss flora there are thirteen families not represented in 
Britain, including fourteen genera and seventeen species. The great 
majority of the latter are escapes from cultivation, or ingrowths from 
the Mediterranean flora, as for example, the Vine, Plane, Walnut, and 
the American Opuntia. The following orders, unrepresented in Britain, 
are probably indigenous to Switzerland : — 
Kutace^c : Buta hortensis, Mill, and Dictamnus albus, L. 
Asclepiadace^e : Vincetoxicum officinale, Miinch. 
Globulariaceae = Selaginiae : Glohularia, three species. 
In all, three orders, four genera, and six species. 
Turning next to the genera, we find that quite 75 per cent, of Swiss 
genera are represented in Britain, and nearly 90 per cent, of British 
genera in Switzerland. 
There are about 140 genera confined to Switzerland, as compared with 
Britain. Of these nearly 40 are only represented by naturalised 
species. This leaves about 100 genera represented in Switzerland by 
indigenous species, of which none occur in Britain. These genera are 
distributed among most of the larger families, especially in the Composita?, 
Graminete, and Crucifera?. 
On the other hand there are about fifty-five British genera unrepre- 
sented in Switzerland, of which ten at least have only naturalised species. 
The Chenopodiaceae is the only family which has a marked increase in 
genera peculiar to Britain, as compared with Switzerland. 
Lastly, in regard to species,'yfe see that 75 per cent, of the British flora 
