274 The Naturalist in La Plata. 
sion of deep internal notes, followed by a set song 
in clear, ringing tones; and then, suddenly taking 
wing, he flies straight away, close to the surface, 
fluttering like a moth, and at a distance of twenty 
to thirty yards turns and flies in a wide circle round 
the female, singing loudly all the time, hedging her 
in with melody as it were. 
Many sonegsters in widely different families possess 
the habit of soaring and falling alternately while 
singing, and in some cases all the aérial postures 
and movements, the swift or slow descent, vertical, 
often with oscillations, or in a spiral, and sometimes 
with a succession of smooth oblique lapses, seem to 
have an admirable correspondence with the changing 
and falling voice—melody and motion being united 
in a more intimate and beautiful way than im the 
most perfect and poetic forms of human dancing. 
One of the soaring singers is a small yellow field- 
finch of La Plata —Sycalis luteola ; and this species, 
like some others, changes the form of its display 
with the seasons. It lives in immense flocks, and 
during the cold season it has, like most finches, only 
aérial pastimes, the birds wheeling about in a cloud, 
pursuing each other with lively chirpings. In 
August, when the trees begin to blossom, the flock 
betakes itself to a plantation, and, sitting on the 
branches, the birds sing in a concert of innumerable 
voices, producing a great volume of sound, as of a 
high wind when heard ata distance. Heard near, 
it is a great mass of melody; not a confused tangle 
of musical sounds as when a host of Troupials sing 
in concert, but the notes, although numberless, 
seem to flow smoothly and separately, producing an 
