BIRDS’ BREASTBONES IQI

The absence or presence of this characteristic
keel or ‘carina’ on the breastbone or ‘sternum’ has
been adopted as the basis of what may be called the
major classification of ordinary birds into Cardnate,
or birds with a keel to their breastbone, and Razite,
or birds with a breastbone as flat as a raft—ratis being
the Latin for that rudimentary nautical invention.
Taking all the birds we know of, an earlier and

 

BREASTBONE OF OWL

equally simple division can be made, for we can sort
them out on their tails—by the tail meaning the real
tail and not the feathers that grow on it—the birds
with tails longer than their bodies being assignable to
the Saurure, the birds with the shorter tails being
further divisible into keeled and rafted, so far as
their breastbone is concerned. These three groups,
Carinate, Ratite, and Saurure, are of equal impor-
tance to the orders of the mammals, and are the only