1889.] Recent Literature. 27% 
and Geese)” are not infallible, any more than human beings are infallible 
in their judgments; and it really cannot be argued that they can a/ways 
foresee these changes. It is well authenticated that in the Outer Hebrides 
Wild Geese on their spring migration northwards are greatly dependent 
on the actual personal guidance of their parents or guardians. An old 
bird distinctly leading detachments, from one favorite feeding or resting 
place to another and returning south again in cases of further services 
being required has been for ages known, and well observed by competent 
observers! What would a flock of geese do if their leader were shot or 
otherwise lost to them, and the flock were all young birds? Certain in- 
stincts wou/d guide them no doubt, but zoz¢ too accurately. 
Returning to the former subject of ‘‘discernment of approaching clima 
tal conditions” I would like to recall the often-observed fact of the disap- 
pearance of mosquztoes fully halfan hour before the first advent of the north 
wind on the tundras of northeastern Europe, as observed, to our intense 
relief, by Seebohm and myself! I say, before the slightest suspicion of 
approaching north wind was perceptible to our senses, the mosquitoes 
suddenly dropped senseless and s#7zg/ess into the wild grasses of the tundra. 
With a sigh of relief, we mutually whispered at last, as we lay watching— 
say a Plover or a Stint to its nest, ‘‘Ah! the north wind!” Then came 
the hurry of the birds up to cover their nearly incubated eggs, in the shal- 
low depressions of the tundra. ; 
Page 13. Now comes a most interesting question. zrs¢, if old 
birds arrive first, they keep bold and jealous charge of their own old 
nesting places. But if young birds arrive first, they are driven away, 
before they can breed, by the older ones if the latter really do ever 
arrive later. I believe the o/d bcrds always arrive first. But in America, 
where the trend of the migration is from north to south and south to north, 
over continuous areas of land, and where every valley and depression 
soon becomes known and recognized by the migrants, old ang young 
travel at the same elevation, or much more approximately so than in 
Europe. But in Europe where the trend of the migration is over both 
land and sea. and persistent in its east to west direction in autumn, and 
vice versa in spring (at least as regards land birds), I deléeve the old 
birds travel ata much higher elevation than the young birds, and travel 
more freely, still guarding the young beneath them. We have still 
to learn much as to the vision of birds, old and young, horizontal 
and vertical, above and below, and we know comparatively little about 
their power in these respects; except that an American astronomer 
is stated to have identified Curlews in the field of his telescope at over 
four miles distance above the earth’s surface, traversing the disk of the 
moon. 
If the American statement that old birds invariably predate the young; 
and the European statement that the young predate the old, are equally 
true, may not the variance be explained thus :— 
In America the trend of the Zavd and mzgration is continuous north 
and south. Therefore, the old and young caz travel over known courses 
at similar elevations, the old gutding the young. 
