Bird Song, and its Scientific Value. By Cuartes A. WITCHELL. 
Read January 12th. 1892. 
The habits of animals are equally with their construction 
worthy of investigation, for movement, especially aberrant 
movement, is the forerunner of new habits, and may therefore 
be termed the parent of physical development. It forecasts a 
possible future, just as structure recalls a certain past. Habit 
is also valuable as indicating the extent to which the multipli- 
cation of certain species may affect human interests; and in 
this it excels physical structure. It is better for us to learn 
what are the seeds devoured by finches, rather than the number 
of feathers of which their tails are composed; yet the books, 
while scientifically accurate in regard to the last feature, 
usually give no more than a vague generalization on the 
former. Aberrations of habit, or even the usual specific signs 
of anger, love, or of hunger, have not generally been recorded 
by ornithologists, who, nevertheless, have pursued with fatal 
activity any specimen which differed, however slightly, in 
colour or in form from a common type. 
We know that during comparatively recent years a change 
of habitat, partial or general, has occurred in certain animals; . 
e.g. the beaver in North America has become solitary; the 
house-sparrow has become parasitical on the abode of man, and 
in that of the martin; the house-mouse is generally dependent 
upon man for food; and the meadow-vole and long-tailed 
field-mouse have adopted walls for a residence. 
But there is another feature in a change of habit, which is 
much more important than its effect upon the distribution of 
species, and this is its suggestion of a mental process akin to, 
or identical with, that which we call reason. The Nuthatch 
(Sitta Europea) affords an illustration. This bird is said to 
crack its favourite food, a nut, after placing it in a crevice, as 
in a vice, for convenience of fracture ; but I have observed this 
Sad al 
