TENTH ORDINARY MEETING, 87 
2. The Canadian Practitioner for January, 1885. 
3. Science, Vol. V., Nos. 100 and 101, Jan. 2nd-and 9th, 1885. 
4. Journal of the Asiatic Society of Bengal, Vol. LIII., Part I., No. 2, 1884. 
Prof. Loudon read a paper on “ The Spherical Aberration 
of Mirrors.” This paper has been incorporated with a former 
paper by Prof. Loudon. (See unite, page 16). 
The Hon. G. W. Allan then read the following paper on 
SOME OF OUR MIGRATORY BIRDS. 
There are few subjects connected with bird life, more interesting 
than the migration of these denizens of the woods and fields, as they 
come to us in Spring after many months of absence—or leave us 
again at the approach of autumn or the keen air of early winter to 
wend their way back to milder and more genial climates. To an 
observant lover of nature there is an especial charm in the recogni- 
tion of the first notes of each winged visitant, heard almost before 
they are seen, and bringing back life and melody to our woods and 
fields after the long silence of winter ; and so again in autumn, there 
seems to be a peculiar plaintiveness in the call-notes of the gathering 
flocks, as if bidding us farewell before setting out on their long 
journey. 
Even winter, however, with its frosts and snows has its visitors, 
coming from still colder latitudes, spending a few brief weeks with 
us, and at the first approach of the sunny days and soft airs of 
Spring, wending their way back to the far North. 
In the limits of a paper such as this I shall not attempt to offer 
anything like an exhaustive list of our birds of passage, I shall 
confine myself to giving, as it were, a rough sketch of the ornitho- 
logical characteristics of each month as marked by the arrival or 
departure of some of the various species of our land birds. 
To begin with the year, for winter, as I have said, has its visitors 
as well as summer, and from the icy shores of Greenland, and the 
frozen north, comes to us that beautiful little bird, the Snow Bunt- 
ing Plectrophanes Nivalis, the harbinger of cold and stormy weather. 
Flying generally in large flocks, as their bodies are seen against the 
blue sky, they look almost like large snow flakes drifting before the 
wind. 
So associated are they with storm and cold that in northern 
