278 Glimpses of Mind in Birds. [May, 
mutes do not occur ; that it is a varied expression of notes, pecul- 
iar to each species, is as well known ; and so, judging these same 
birds from a human stand-point, they assuredly know themselves 
and understand each other, have đefinite expressions for certain 
conditions, have, in fact, the gift of language as the natural out- 
come of that power of thought which their methodical lives show 
they duly exercise. 
The presence or absence of food in any given locality is also 
rightly supposed largely to influence the stay or departure of all 
birds, either resident or migratory ; but let us take the instance 
of the roving purple finches I have referred to. In this case 
there was doubtless an abundance of food available for weeks in 
the little wood in which they tarried for so short a time. They 
certainly did not remain long enough to determine that point, 
and so gave evidence of a predetermined journey to some partic- 
ular point, towards which they were moving when I chanced 
upon them. On these same. oaks and about the hill-side gener- 
ally, scores of times I have seen these finches often for days to- 
gether, and consequently finding sufficient food. When I last 
saw them they were not seeking out better feeding grounds than 
those they had left, bút a locality otherwise more suitable. If, 
then, there is in the character of these migratory movements 
even a trace of predetermination, does it not bear directly upon 
the question of the conveyance of impressions from one to the 
other? and if the sounds they utter are closely related to their 
movements, can we conceive of these as having any other signifi- 
cance than that of being the means: by which they express their 
thoughts, —that their utterances are strictly a language? One 
can easily believe that an elaborate song is a pleasure to the lit- 
tle musician himself as well as all his hearers, and may be given, 
. perhaps, with a wholly selfish intent; but not so can we explain 
away the endless chirps and twitters expressed during the ordi- 
nary routine of each day’s existence. 
Again, as bearing upon the subject of birds’ flocking, together 
with their various “ notes” or language, it is to be borne in mind 
that widely different species do not migrate together, but on 
the other hand, allied species and genera are thus associated, and 
there is a marked similarity in very many of the “ calls ” of these 
allied species, as well as identity in habits and preference for the 
same localities. And are not these facts, by the by, suggestive 
of the great probability that in the distant past the variations 
now existing in our widely different birds were far less in num- 
