1877.] Glimpses of Mind in Birds. 277 
numbers for many weeks, and after a longer or shorter absence 
as suddenly to return to their accustomed haunts. More partic- 
ularly is this the case with our winter residents. It is generally 
supposed that these semi-migratory movements are in conse- 
quence of meteorological conditions, the birds having the power 
to foretell a change by recognizing it through alterations in in- 
animate nature, not appreciable by man, or more probably by 
electric conditions acting directly upon them, on the same princi- 
ple that a gouty big toe is an excellent barometer. Granting that 
these sudden departures from a given neighborhood by any spe- 
cies of birds or by the birds generally are caused by a meteoro- 
logical influence, operating on each individual alike, would they 
not then go as individuals from the locality where the influence 
is felt to one better suited to them, during the prevalence of the 
obnoxious conditions? Every bird would then become a mere 
automaton, wafted to and fro at the mercy of the winds and 
clouds. While I do admit that the weather is the determining 
cause of the birds’ movements, I am convinced that the influence 
is exerted in a somewhat different way. These temporary mi- 
grations are not made individually, but collectively, the birds 
maintaining a close association, their numbers not varying be- 
tween the times of their departure and arrival. No meteorolog- 
ical influence could produce a flocking of any species, as repre- 
sented in a given area, previous to forcing or at least inducing 
them to quit the neighborhood. Now, if we allow to birds exact. 
geographical knowledge of a considerable extent of territory, then 
experience will have taught them, without doubt, that a ravine 
extending at right angles to the track of a storm is a proper shel- 
ter while the storm or “ spell of severe weather ” lasts ; and the 
atmospheric conditions pending the change admonishing them, 
the scattered birds would depart thereto and arrive singly from 
every quarter, congregating for the first time when safely in 
the protecting ravine; but this is not found to be the case at all. 
ey congregate wherever they may happen to be, and this ne- 
cessitates an uttered signal, understood by them. Once collected 
they determine their route and depart in company. In Decem- 
ber last, as I have related, I met with two such flocks of migrat- 
ing birds. In thus associating they must derive either benefit or 
Pleasure, if not both. If benefit, it must be that a mutual un- 
derstanding exists among them; if pleasure, there must be an 
Mterchange of the impressions made upon one to the other. 
at it is an audible interchange we all know, for flocks of 
