FLIGHTLESS BIRDS. Ls: 
feathers were originally developed, without which purpose 
they have no meaning. 
The sternum of Apteryx is a small quadrate bone with 
wide anterior emargination, and rather deep notches pos- 
teriorly, caused by the projection of the posterior lateral 
processes. It is usually quite smooth on the anterior 
surface, like that of Ratites generally, but in two or three 
cases, T. J. Parker found a distinct median longitudinal 
thickening along the anterior half of the front of the 
sternum, which formed in fact a low keel. This is very 
significant, as it probably indicates reversion to a time 
when the bird possessed a keel to its sternum, and therefore 
the power of flight. The coracoid and scapula are 
ankylosed together at an open angle, after the manner of 
Ratites generally, and there is no furcula. 
With respect to the fore-limnb the only thing that need 
be noted with reference to the humerus, radius, and ulna, 
is their very small size. 
As regards the manus, in a specimen of A. australis, 
figured by Parker, there is no separate carpus, the bones of 
the fore-limb being succeeded by a single irregularly- 
flattened bone, the carpo-metacarpus, to the distal end of 
which is attached a single digit consisting of three phal- 
anges. ‘T'here is, however, some variety in these respects, 
both in different species of Apteryx and in different speci- 
mens of the same species, some showing remnants of a 
carpus in the shape of a single small bone and the meta- 
carpus giving indications of a separation into component 
parts. In no ease is there more than one digit. During 
development, however, there are always definite indications 
of a carpus and of a division of the single metacarpal bone 
of the adult into three segments ; so that, in development, 
the skeleton of the fore-limb follows the same lines as 
those of a true wing, 
