112 
ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 
(the vernal equinox) their numbers were greatly increased. They breed in central 
Chile, and replace, as I have before said, the foregoing species, which migrates 
southward for the same purpose. The nest is deep in proportion to its width ; 
externally three inches and a half deep ; internal depth a little under one inch 
and three quarters ; width within one inch and two-tenths ; mouth slightly con- 
tracted. Externally it is formed of fine fibrous grass woven together, and attached 
by one side and bottom to some thin upright twigs ; internally it is thickly lined 
with a felt, formed of the pappus of some composite flower. When on the wing, 
the appearance of this bird is singular. Like others of the genus, it moves from 
place to place, with a rapidity which may be compared to that of Syrphus 
amongst diptera, and Sphinx among moths ; but whilst hovering over a flower, 
it flaps its wings with a very slow and powerful movement, totally different from 
that vibratory one common to most of the species, which produces the humming 
noise. I never saw any other bird, where the force of its wings appeared (as in a 
butterfly) so powerful in proportion to the weight of its body. When hovering by 
a flower, its tail is constantly expanded and shut like a fan, the body being kept 
in a nearly vertical position. This action appears to steady and support the bird, 
between the slow movements of its wings. Although flying from flower to 
flower in search of food, its stomach generally contained abundant remains of 
insects, which, I suspect, are much more the object of its search than honey is. 
The note of this species, like that of nearly the whole family, is extremely shrill. 
In the Appendix an anatomical description of this bird by Mr. Eyton is 
given. 
Order— SCANSORES. 
1. CONURUS MURINUS, Kulll. 
Psittacus murinus, Gmel. 
Perruche, Pernet , voy. 1. p. 312. 
This parrot feeds in large flocks on the grassy plains of Banda Oriental, where 
not a tree can be seen. They are very destructive to the corn-fields. I was 
assured that in one year, near Colonia del Sacramiento, on the north bank of the 
Plata, 2,500 were killed, a reward being given for each dozen heads. Many ot 
these birds build their nests close together in trees, the whole composing a vast 
mass of sticks. I saw several of their compound nests on the islands in the river 
Parana. 
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