EVIDENCES FROM MORPHOLOGY 137 
organism presents corresponds, in a general way, with the length of 
- time during which the divergence has been going on. Thus we 
PTERNUM 
» 
Fic. 15.—Skeleton of Dinornis gravis, js nat. size. Drawn from nature 
(British Museum). As separate cuts on a larger scale are shown, (1) the sternum 
as this appears in mounted specimens, and (2) the same in. profile, with its 
(hypothetical) scapulo-coracoid attached. (From Romanes.) 
scarcely ever meet with any great departure from the typical form 
with respect to one of the organs, without some of the other organs 
being so far modified as of themselves to indicate, on the supposition 
