Ten sae ta 8) 
or Toothed Birds of North America. 263 
Wings Slowly diminished in size, first came the loss of flight, 
while the Wings retained, doubtless for a long time, their power 
aken place in ocean navigation, in the gradual change of the 
Side-wheel steamer into the modern propeller. 
‘ Another explanation seems on the whole more reasonable, 
4nd more in accordance with the known facts. The Struthious 
characters, seen in Hesperornis, should probably be regarded as 
given similar characters to the Ratite, and subsequently have 
T- 
cae long neck and peculiar jaws and teeth would be nt Bae 
* 
