FLORA OF ARROCHAR MOUNTAINS. . 89 
which ascend the mountains and those which are confined to the 
lowland areas. Ina large number of cases the limits of altitude 
have been determined, and, in all such cases, the highest point at 
which the species was observed is given ; and, in the case of alpine 
species, the lowest limit as well. It must, however, be carefully 
borne in mind that these limits apply only to the hills specified, 
and may not, in any one instance, agree with the altitudinal range 
of the species in other localities. I am aware that questions of 
altitude are apt to be dealt with erroneously when attention is 
confined to a single district, and, more especially, when the locality 
selected is of so restricted an area as the one we are dealing with ; 
but, in order to a wider generalisation, it is of importance that the 
facts with regard to definite localities should be accurately ascer- 
tained, and from this point of view our present figures may not be 
without value. 
With reference to the vexed question of the definition of the 
word “alpine” as applied to plant forms, I may explain that 
throughout this list I have used the term to signify a plant which, 
as regards these particular mountains, is confined to the higher 
altitudes, not descending below 1,000 feet. It will be seen that 
this does not in all cases correspond with the applicability of the 
term in other localities. There are some species which are 
frequently found at lower elevations in different parts of the 
country, but which are here characterized as “alpine” from their 
occurring in the Arrochar district only on the higher parts of the hills. 
In the compilation of the list I have made use of all the material 
to which I have been able to obtain access. In the great majority 
of cases, the species has been gathered by myself in the locality 
indicated ; in other instances I have given the source from which 
the information is derived. I would take this opportunity of 
expressing my indebtedness to those members of the Society whose 
notes have been freely placed at my disposal, for their valuable 
assistance in making the list as complete as possible. Doubtless 
there are many important omissions, and I shall be greatly pleased 
if the present paper is instrumental in bringing to light any further 
information at present unrecorded. 
I have to acknowledge, in particular, my indebtedness to 
Mr. P. Ewing, for his invaluable assistance with some of the larger 
critical groups, such as Hieracium, Salix, and Carex. 
