ty 
AERATION OF CHAUNA 
placed the birds known as Screamers or Kamichis, 
known to us by three species, usually referred to two 
distinct genera, viz. Chauna and Palamedea. The 
Derbian or the crested screamer (Chauna derbtana and 
C. cristata) is a bird which looks like nothing else in the 
bird way. It has the head of a fowl attached to the body 
of a good-sized goose, the whole surmounted upon 
longish legs with straddling toes. The long legs suggest 
wading, and the large “ feet’ with divaricated toes safe 
progression upon treacherous and marshy soil. The 
bird is in fact at least partly aquatic; and the likeness 
to a goose is not wholly a matter of outward appear- 
ance. But it cannot be definitely placed in that large 
order, which includes the geese, swans and ducks; 
rather is it to be looked upon as the vestige of a group 
which perhaps produced, as a mere side issue, the anati- 
form birds. The mainstem with its archaic characters 
has come down to us in these three desolate birds which 
form the subject of the present article. 
The chaunas have a puffed out and even gouty appear- 
ance about the legs. Coupled with a slowish gait this 
suggests overfeeding, a complaint which is not un- 
known at the Zoo through the unnecessary kindness of 
visitors. It is, however, merely a conspicuous expres- 
sion of a state of affairs which characterizes birds in 
general and not the screamers only. These birds, 
like others, are literally ‘“‘ puffed out with wind and the 
rank mist they draw”’ in order to lighten their some- 
times cumbrous bodies. The lungs of birds are not 
simply bags more or less subdivided into multitudin- 
ous chambers as in ourselves and other animals; but 
they communicate with a complex system of ramifying 
‘air cavities spread through the body and permeating 
even their very bones. There is hardly a portion of the 
bird’s body which is free from air-containing spaces, a 
state of affairs which obviously aids it in spurning the 
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