Prof. R. Owen on the Solitaire. 97 
been made by the author or acceptors of this hypothesis as to 
the way of operation or conditions of the transmutation. 
In most of the instances of wingless birds affinity to more 
favoured or normal members of the feathered class has been 
traced. 
The Penguins (Jmpennes) cannot be dissociated from the 
smaller Urinatores, which retain the volant function of the 
wings. 
Alca impennis is not generically separable, in judicious taxo- 
nomy, from the swiftly flying Alca torda. 
The genera Aptornis and Notornis, with keelless breast- 
bones, cannot be divorced from the family of Coots. 
Cnemiornis, although also with a “ ratite’’ or uncarinate 
sternum, must stand, besides Cereopsis, in the Anserine group 
of Anatide. 
The Didines are but generic modifications of a great natural 
division of Rasores, the existing members of which, of smaller 
size, retain their faculty of flight. 
Dinornis shows the consequence of disuse of wings in a 
greater degree than does Apteryx. But, although the winged 
forms from which the Kiwi, the Cassowary, the Emu, the Rhea, 
the Ostrich, and the Mpyornis have severally degenerated 
remain to be determined, they each have structural character- 
istics encouraging the quest, and testifying against the artifi- 
cial group (Megistanes, Vieillot; Procerz, Llliger; Ratite, 
Merrem ; Struthionide, Vigors) based upon modifications of 
the breast-bone and scapular arch, the consequences of disuse 
and degeneration of the muscles of flight, and with which a 
loose character of plumage is more or less associated. 
The results of the researches which have determined the 
real affinities of extinct birds with keelless breast-bones and 
low-angled scapulo-coracoids, devoid of acromial and clavi- 
cular processes, supports a reasonable expectation that the 
existing wingless genera, which have been shown to differ 
from one another considerably in important anatomical struc- 
tures, in correlation with their distinct and remote habitats, 
will be ultimately referred to as many distinct natural groups 
which now are, or which formerly have been, represented by 
volant and typical members of the feathered class. 
EXPLANATION OF THE PLATES. 
Prate VII. 
Fig. 1. Reduced side view of the skeleton of the male Solitaire. 
Fig. 2. Occipital surface of cranium, natural size. 
Fig. 3. Copy of a figure of the living Solitaire, from the frontispiece to 
Leguat’s work, above cited. 
Ann. & Mag. N. Hist. Ser. 5. Vol. i. é 
