PEDIGREE OF BIRDS 775 



ment of some Birds reveals many remarkable resemblances 

 with that of Reptiles — therefore, v/ith the strength of the 

 general argument for evolution to corroborate us, we 

 conclude that Birds evolved from a Reptile stock. This 

 stock may have been among the bipedal Dinosaurs known 

 as Ornithischia ; but there are also strong arguments for 

 regarding another order, the Pseudosuchia, as ancestral. 



It is likely, then, that Birds arose from an ancient Saurian 

 stock, but by what steps and under what impulses we do 

 not know\ To some it seems enough to say that the 

 evolution was accomplished gradually in the course of 

 natural selection by the fostering of fit variations and the 

 elimination of the disadvantageous ; to others it seems that 

 the incipient birds w'ere '* fevered representatives of reptiles, 

 progressing in the direction of greater and greater con- 

 stitutional activity " ; but both these suggestions leave 

 much in the dark, leave us still to '' wonder how the 

 slow, cold-blooded, scaly beast ever became transformed 

 into the quick, hot-blooded, feathered bird, the joy of 

 creation." But we must think not of transformation^ but 

 of origination and divergence. 



