22; TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
been capable of limited flight. Other examples might be 
named; and if we were to include brevipennate birds with 
very limited powers of flight, such as Geopsittacus, the 
Ground Parrot of Australia, which are, as it were, on the 
highroad to becoming flightless, the list might be consider- 
ably extended. It would be possible, indeed, with the aid 
of intermediate forms, to construct a complete series from 
strong flying to completely flightless birds. Doubtless, 
also, many more forms have disappeared altogether with- 
out, alas! the opportunity having been afforded to any 
naturalist of observing and studying them. ‘To attempt 
to examine all these species in detail is, of course, imprac- 
ticable here, and it must suffice very briefly to review the 
three typical examples furnished by Didus, Notornis, and 
Stringops. 
Here is the familiar figure of the Dodo, a large uncouth 
bird about the size of a Turkey, with a huge raptorial 
looking beak, stout and strong legs and feet, mere apologies — 
for wings, and a few curled feathers by way of a tail. 
When Strickland and Melville wrote Gn 1848) their well- 
known monograph on this bird, comparatively little was 
known of it, and but few remains of 1t were extant—a foot 
in the British Museum, a head and foot at Oxford, and a 
head at Copenhagen being all the fragments in existence. 
Much difference of opinion has existed as to its affinities. 
It has been referred by some to the Struthious family, by 
others to the Gallinaceous birds, and by others again to 
the Raptores. But Prof. Reinhardt of Copenhagen, as far 
back as 1845, from an examination of the skull of this 
bird, existing in the museum of that city, gave it as his 
opinion that the Dodo was a greatly modified pigeon, and 
should, therefore, be classified amongst the Columbe, an 
opinion which was adopted and emphasised by Strickland. 
The acumen of the Danish professor has been abundantly 
