1889.] Development of Bird Language. lOi 
however, the result of Darwin's life-long study of psychical and 
physical evolution receives wonderful confirmation in the fam- 
ily resemblance of notes peculiar to species whose genealogies, 
according to the development hypothesis, are tracable to the 
same ancestry. The Icteridae form a group, the genera of 
which emphatically demonstrates this. 
In the song of the Bobolink, a well known representative, he 
who runs may read a sure word of prophecy, proclaiming to 
the ear in its every emphasis, the same scientific facts as does 
his anatomy to the eye. 
Who, that hears him say, in lusty May-song, " I'm a finch, 
I'm a finch. Icterus, Icterus, Quiscalus, Molothrus, Sturnella, 
one and all ; as you'll see if you look at me, chee ! Agelaeus 
et cetera, all linked in me, a bobolink, bobolink, as you can 
see ! " — dare contradict a word of it on biological grounds ? 
Not less confirmatory of this and of the theory of the mini- 
itic origin of bird notes is the evidence given by species of 
widely separted generic characters which frequent the same sort 
of habitat and are subject during life to the same environing 
influences. 
Some of these, as the Robin, Scarlet Tanager, Rose-breast 
Grosbeak and Baltimore Oriole, have song- notes in common, 
while the Woodcock, Night- Hawk and Snipe, have nearly 
the same squeaking call-note when associated together at night 
as frequently happens, thus indicating that their inspiration 
was derived from like natural sources, and that, in harmony 
with their limited vocal needs, it has remained content with 
' squeaking. But, strange to relate, the members of this same 
trio have each made an attempt at something higher, and, 
(which is stranger than all) with nearly identical results. In 
the Goatsucker it is a hollow, booming sound, produced by its 
sudden downward descent during flight; in the Snipe and 
Woodcock it results from a whirring of wings during a slowly 
ascending and descending spiral flight. Such is the commonly 
accepted belief of observers of these manoeuvres, and, if correct, 
they illustrate how, in the retarded organic development of 
any faculty, nature supplements it by mechanical ingenuity. 
