The Tufted Duck in Scotland. 147 
Muonio river and the great Lake Enare contribute some 
quota vid the Bothnian Gulf and Baltic there is no positive 
reason to doubt. 
That any, or at least many, cross the high backbone of 
mountains of the Scandinavian peninsula from Lapland and 
Finmark at once after leaving their summer quarters, upon 
an east to west route, is, I consider, extremely unlikely, and 
I cannot think we have any evidence to show that such is 
the case. The few pairs, or, let us say, the comparatively 
small community which is reported as nesting in Northern 
Norway, is more likely to have obtained its meagre supply 
from birds which, pursuing a course east to west along the 
North European coasts, have reached their turning point at 
the North Cape. In 1872 Herr R. Collett reported the 
species as “nowhere numerous” in North Norway, and in 
1891 he is silent as to any increase. As Palmén has lucidly 
explained—Migration routes are not irregular, but can be 
geographically determined. These routes lead from the 
north to the south, for different species, in the most various 
directions; but, he adds significantly, “in places outside or 
between these routes the birds do not usually occur”—z.e., 
the birds of the species specially referred to by him. 
Indeed, as I think can be gathered from our entire accumu- 
lation of facts, this species does not appear to take delight in 
crossing any high ridges or chains of mountains when on 
passage to and fro either in autumn or spring. The tendency 
of the species is distinctly to become sedentary or stationary 
once it has taken up and occupied new breeding centres. 
And this, I think, is the place where I desire to say— 
while I have spoken of, and will likely use again, the terms 
“lines of least resistance” and “general migration flight,” 
I do not wish to be understood to mean thereby any refer- 
ence to the higher air strata at which it has been shown that 
many birds travel. That is a somewhat different and possibly 
a more difficult branch of the subject. I am only speaking 
of the influence of land-contours as may be presented 
to bird’s-eye views from comparatively low sky-altitudes 
when birds are approaching downwards and landwards for 
purposes of feeding, rest on a journey, or arriving at their 
