PROF. T. H. HUXLEY ON THE GENTIANS. 119 
the highlands of Northern Arctog»a and of Austro-Columbia, 
the contrast between the Gentian Flore of the two becomes 
still more striking. 
In Sir Joseph Hooker’s well-known paper “On the Distribu- 
tion of Arctic Plants ” (Transactions Linn. Society, vol. xxiii.) , 
the following twelve Gentiane® are stated to occur north of the 
Arctic Circle :—Gentiana aurea, propinqua, detonsa, arctophila, 
Amarella, tenella, glauca, prostrata, nivalis, verna ; Pleurogyne 
rotata, Menyanthes trifoliata. 
I have not examined Gentiana arctophila ; but I believe it to 
belong, like G. aurea, propinqua, and detonsa, to the Actinanthe 
type. In this case the components of the Gentian Flora of the 
Arctic regions may be classitied as follows :— 
Actinanthe. Keratanthe. Lophanthe. Stephananthe. 
5 0 0 2 
Limnanthe. Asteranthe. Lissanthe. Ptychanthe, 
1 0 0 4 
In the Flora of the European Alps I can find no representa- 
tive of the Actinanthe type except Pleurogyne carinthiaca. On 
the other hand, two of its Gentianes, Gentiana ciliata and 
Swertia perennis, belong to Lophanthe. 
Passing to the Stephananthe type, Gentiana tenella is admittedly 
common to the Alps and the Arctic regions ; but the former 
have G. germanica, campestris, and nana in place of G. amarella. 
How far any real distinction is to be drawn between G. amarella 
and G. germanica is a question for future examination. 
Limnanthe is represented by Menyanthes trifoliata i in both the 
Arctic and the Alpine regions; Asteranthe only in the Alpine ; 
Lissanthe in neither. 
The ordinarily recognized species of Ptychanthe in the proper 
Alpine region of Europe are some eighteen or nineteen in number. 
Three of these, namely, G. verna, nivalis, and prostrata, are also 
Arctic; but the Gentians of the “acaulis group, which flourish, 
along with verna and nivalis, in the Alps, are unknown in the 
Arctic regions. Again, the Gentians of the purpurea group, 
though they occur in Southern Scandinavia and Kamtschatka, 
stop short of the Arctic Circle. 
.. It appears to me that these facts are very difficult to reconcile 
with the view that the high Alps have been peopled with their 
Gentianex from the Arctic regions or vice versé. The abundance 
