Hart — On the Mountain Flora of Ireland. 669 
flowering. Others flowered, but so late in the season that they had 
no chance of ripening their seed ; although the year was by no means 
unusually harsh so far as we could judge. Whether these species are 
being gradually exterminated (such as Cardamine pratensis, JEpilolium 
latifolium^ &c., in Discovery Bay) from a gradually increasing severity 
of climate, it may be impossible to say, but it seems not unlikely. I 
have no doubt it is possible that I stated the case in too wholesale a 
manner in my Paper. But there is undoubtedly a basis for argument. 
The reason I introduced this remark here is that in Ireland we are, as 
it were, at the other end of the tether, and our Alpine flora which 
must in all probability have been much more considerable at some 
period since the close of the glacial epoch than it is now, is a slowly 
expiring quantity. Some species are no doubt modified to suit their 
present condition and will hold their own. But I could not fail to be 
reminded of my former deduction when I gathered Aralis petroea on 
Galtymore in an absolutely barren condition in its most southern 
station in the kingdom. And especially as it has taken five years 
oi careful nursing to make specimens of this Alpine brought home 
from there produce flowers. Again, I found Dryas octopetala in its 
ionly situation in Donegal restricted to a single patch, and unfailingly 
)barren year after year. One or two other species from different parts 
of Ireland could be quoted to the same effect, and it would be an 
important deduction could we determine that the first step towards 
extermination by natural causes was the non -production of seed 
whether from diminution of requisite sun-heat, or the destruction of 
fertilizing insects by slow change of climate. In the Arctic regions 
the battle would be longer since there is less competition. In our 
climates any weakness will soon compel the straggler to cease from 
the combat. 
With this digression I bring this Paper to a close. I have ven- 
tured farther than I intended in pointing out a proposed classification 
for Irish plants according to their distribution. I think it will be 
found helpful to a student of Irish botany, although some unruly 
species will be found difficult to fit to any of my suggested groups. 
Had I space, I believe I could, however, by a detailed enumeration 
point out that almost the whole of our plants give little difficulty. 
R.I.A. PROC, SER. III., VOL. I. 
