204 NEW YORK ZOOLOGICAL, SOCIEDY 
races which flourished in past ages and now linger only in a few 
isolated localities. 
Of all birds they are the most unbirdlike, combining charac- 
teristics which are extremely specialized with others which are 
startlingly reptilian. 
In many ways these birds stand alone, sharply set off from 
the great Subclass of flying birds; yet, such is the homogeneity 
of all birds—so similar is the structural mould in which they are 
all cast, that there is actually less difference between the two 
extremes—an ostrich and a crow—than between a marine turtle 
and a land tortoise, or a common lizard and a chameleon, mem- 
bers of comparatively subordinate groups of reptiles. 
During the Mesozoic Age, reptiles ruled the earth by means of 
their great size and fierceness. Following hard upon their de- 
cline, the mammals came to the fore. During all these millions 
of years untold numbers of birds lived and died, taking small 
part in the great struggle for supremacy, but keeping to the 
branches and leaves of the conifers and cycads of those ages. 
At some time in this mysterious past, how and when we can 
only guess, several groups of birds found certain places of refuge, 
widely isolated, where, by flying less and trusting more to speed 
in running, they were able to avoid their enemies, live and mul- 
tiply. These were the ancestors of the living Ostriches, Rheas, 
Emeus, Cassowaries and Apteryges, which form the subject of 
the present paper. : 
We may cite Archaeopteryx, the famous bird of the Jurassic 
period, with its lizard’s tail, teeth and claws, and its bird’s beak, 
feathers and feet, as perhaps representing the avian stem before 
the ancestors of the Ostriches began to diverge from an arboreal 
and volant condition to one which eventually resulted in making 
them wholly terrestrial and cursorial. 
A thrush will serve as an example of one of the highest groups 
of those birds which, holding true to the traditions of their an- 
cestors, kept to the tree-tops, becoming expert flyers, and gaining 
in sweetness of voice and in tint of feather, rather than in mere 
grossness of size. 
TELS VASP TE RYE 
In New Zealand we find the Apteryx, the most diminutive 
and defenceless of the Ostrich tribe, yet living in safety in this 
isolated land until man came with his guns and dogs. The days 
of the Apteryx are now numbered. It is about the size of a 
domestic fowl, and is covered with long, loose, hair-like feathers. 
