14. TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
Asin the bones of the fore-limb, so in the muscles, there 
is distinct evidence of degeneration, but the wing has the 
usual flexors and extensors, and also a good development 
of muscles acting as pronators and supinators. 
To these facts, all pointing unmistakably to this bird 
having passed through a flying stage others might be 
added, but I think I have pointed out enough to indicate 
at any rate the strong probability that the ancestor of 
Apteryx, in remote time, was a bird which possessed the 
power of flight. And if this can be considered proved of 
Apteryx,it may, I think, be safely asserted of the remainder 
of the existing Ratites. If, however, we turn to the gigantic 
extinct Ratite birds of New Zealand, comprised under the 
general term ‘‘ Moas,” we find a still further degradation 
of the wing, to such an extent indeed that it is doubtful if 
it existed at all. 
Dinornis may be taken as the type genus of this group 
of birds, which were very numerous, and the remains of 
which have been divided up into five genera, and about 
twenty-five species. One of the most striking features of 
the group is the immense size reached by some of the 
species; Dinornis maximus, for instance, had a tibia 
measuring 89 inches in length, and this bird probably 
attained a height of 12 feet. Their great numbers 
indicate that the conditions under which they flourished 
must have been very favourable to their existence. With 
the advent of man upon the scene, however, the balance 
of nature was upset, and they were exterminated for food 
by the native Maoris long before any Huropeans set foot 
in the country. ; 
But the condition of the shoulder-girdle and its con- 
nections is what has most interest for our present enquiry. 
The sternum was a smooth, sub-quadrate, more or less 
flattened bone, with a pair of deep and wide posterior 
