497

463

processes for muscular attachments, to the scapula, coracoid, furculum, brachial and
antibrachial bones, carpus, metacarpus, limited number of digits, and their extremely
modified phalanges, of the perfect instrument of flight in truly winged birds.

The minor modifications of the volant mechanism characteristic of the Columbacei are
as plainly demonstrable in Didus and Pezophaps as are those of the Coots in the minor
modifications of the useless wings of the Cnemiornis - 'useless,' in such instance, referring to
the act of flight.

These comparisons and considerations lead me to regard the Dodo as a degenerate
dove. It exemplifies the origin of a species agreeably with the partially applied hypo-
thesis of Buffon 1, and through the way of operation of the secondary law of the origin
of species suggested and advocated by Lamarck 2.

The same course of argument which has been suggested by the impennate Awk of
northern shores and the flightless Doves of the Mascarene Islands applies, as we have
seen, to the Moas of New Zealand. But in these the degree of atrophy, which seems
to have been carried to total loss, of the limb-appendages of the scapulo-coracoid arch
implies the operation of the influence of disuse through a period of pre-Maori aeons
greatly exceeding the time during which the Lamarckian law has operated on the Cas-
sowary, the Rhea, and the Ostrich.

In reference to the subject of the foregoing speculation, another hypothesis has,
however, been propounded, viz. that birds are transmuted and advanced Dinosaurs,
and that the feathered, hot-blooded, quick-breathing class made its first step in life-
promotions from naked, cold-blooded, slow-breathing reptiles, under the low form
of Struthiones or Cursores, as yet incapable of flight 3.

According to this view the Dodo is a predecessor of the Crown pigeon, the Notornis of
the Coot, the Cnemiornis of the Goose, and the Dinornis of some, as yet, unknown winged
form, unless the course of evolution, through the Moas, has come to an untimely end.

Alleged facts of embryology have been adduced in support of this idea, and the
assertion has been hazarded that "if the whole hind quarters, from the ilium to the
toes, of a half-hatched chicken could be suddenly enlarged, ossified, and fossilized as
they are, they would furnish us with the last step of the transition between Birds
and Reptiles ; for there would be nothing in their characters to prevent us from referring
them to the Dinosaurs."

I am barred, however, from joining the biologists indicated by the plural pronoun,

1 'Histoire Naturelle,' tom. xiv.p.311, 4to,1876. Buffon does not enter into the conditions of degeneration
of parts.
2 'Philosophie Zoologique,' 2 vols. tom. i. chaps. iii.,vi.,vii., Svo, 1803. On the influence of exercise and
of disuse in altering the proportions of parts and organs.
3 Prof. Huxley, 'Quarterly Journal of the Geological Society,' vol. xxvi. p.20.