266 Dwicut, The Philadelphia Vireo. aw 
only ten feet from the ground in the twigs of a willow. It contained 
four eggs on the 13th of June, which resembled the eggs of the 
Red-eye but unfortunately were accidently destroyed. I used 
sometimes to meet with incubating females that made very little 
fuss, perhaps merely leaning forward from a branch near at hand, 
the crown feathers raised in silent inquiry. But usually they gave 
vent to their disapproval of my presence in bursts of vigorous 
mewing notes in which the male heartily assisted. He does not, 
however, assist in incubation, like his relation the Warbling Vireo, 
but devotes himself to melody, and a very cheerful melody it 
1s too. 
SONG. 
To my ear the song partakes of the liquid sweetness and 
leisurely irregularity of that of the Solitary Vireo, the notes being 
sweeter, clearer, and a trifle higher pitched than those of the Red- 
eye. Itis no easy matter to describe the song of a bird intelli- 
gently. We do not know their language nor have we alphabetical 
signs or musical notation, that can convey to us more than a faint 
idea of bird music. Fortunately we have comparisons to fall back 
upon, and as the song of the Red-eyed Vireo is well known to 
many of us, some idea of that of the Philadelphia Vireo may be 
gained when I say that while the former rapidly ripples out his 
music, the latter reiterates slowly a series of double or triple 
notes with marked pauses between. My experience has been 
that having once heard philadelphicus you will seldom mistake it 
for olivaceus, while the reverse will not hold. There is more 
reduplication of notes in the song of the Red-eye and one might 
say, less time for taking breath. In Mr. Brewster’s account of 
the birds, which I can corroborate in every particular, he speaks 
of a “double-syllabled utterance’? coming in irregularly with the 
general song. I would merely emphasize the fact that it is the 
essence of the song and enters into it at as regular intervals as 
any of the other notes. It is a liquid note, beginning the song 
and occupying about three fifths of a second for the two syllables 
of which it is composed, on both of which considerable emphasis 
is laid. There seems to be a slight trill or ripple between the 
