CIVILIZING. INFLUENCES. 197 
increase. This can be owing only to the fact that by cut- 
ting down the forests, etc., civilized man has tempered the 
rigor of the climate, has multiplied the sources of bird 
food, has appended many additional places suitable for the 
young, and has enabled more fledglings to be brought to 
inaturity by reducing the ranks of the enemies of the birds. 
This has not only augmented their number, and very ap- 
preciably modified their habits of nesting and migration, 
but probably has somewhat changed even their physical 
and mental characteristics. There is little doubt in my 
mind, for instance, that in making their lives less laborious, 
apprehensive, and solitary, man has left the birds time and 
opportunity for far more singing than their hard-worked, 
scantily-fed, and timorous ancestors ever enjoyed—a privi- 
lege a bird would not be slow to avail itself of. 
But, on the other hand, it seems to me equally certain 
that the music of our more domestic birds, though greater 
in volume, is not so sweet in tone as that of their wild- 
er brethren. Our foreign street sparrows (the London 
“ Jims”) are naturally, I suppose, rather harsh-voiced ; but, 
whatever they might have been a thousand years ago, they 
could hardly be otherwise now, when the rattle-te-bang of 
the city pavements has been their only teacher for many 
centuries. The mocking-bird has learned to imitate the 
