ZOOLOG Y. 67 
the running birds are older than the ordinary birds; this 
harmonizes with the fact that the running birds are of 
existing birds the most nearly allied to the Dinosauria, the 
supposed ancestors of birds. The birds called Penelope 
(Cranes) are generally classed with the scratching birds, but 
they seem to be more nearly allied to the Rhea, Emeu, 
and Cassowary, and are joined with them, and called by 
Haeckel Saurophalli. The tree of descent would be then 
Dinosaurian reptiles, represented by Compsognathus, etc. 
Changed into Archeopteryx-like forms, the most ancient 
of birds, the modified posterity of the Archeopteryx would 
be represented by the Penelope, Rhea, Emeu, Cassowary, 
having three toes. The African Ostrich, having only two 
toes, is probably more modern than the three-toed South 
American kind, or Rhea. The Cassowary, through the 
Dinornis, leads up to the Apteryx, while the Enieu and its 
posterity seem to have remained unchanged. The Penelo- 
pidz are probably the ancestors of the scratching birds, to 
which are nearly allied the recently extinct Dodo of the 
Mauritius, and the doves and pigeons. The ducks seem 
to form the transition between the Saurophalli and the 
swimming birds, though it must be remembered that the 
Penguin in its separated metatarsals (bones of the foot) 
would indicate an ancient bird. The swimming birds gave 
rise probably to the wading birds. All these birds, except- 
ing the doves, leave the egg in a condition fitted to nourish 
themselves; whereas the doves, pigeons, etc, and their 
descendants, leave the egg blind, and are nourished by 
their parents. The pigeons and doves, descending through 
the Pteroclidae from the scratching birds, probably divided 
into two branches, the Clamatores (crows, etc.) and the 
Climbers (woodpecker, etc.); the Clamatores were gradually 
improved into our singing birds, and the climbing birds 
into birds of prey. 
"ecu 
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