THE EMPIRE OF THE GREAT REPTILES. 179 



their allies, and the peculiar Mesozoic birds, such as Arc/uc- 

 opteryx. The first would serve to account for the few excep- 

 tional Struthious birds of the modern world. The second 

 would account for the Passerine and other more ordinary birds ; 

 and thus, according to evolution, the now somewhat homo- 

 geneous class of birds would have a double, or more probably 

 multiple, origin from several lines of reptilian ancestors. This, 

 no doubt, greatly complicates the links of connection, whether 

 these be supposed to indicate derivation or not. 



Fig. \^A,.—Compspgnathus. One of the smaller Dinosaurs. -A*"ter \V; 



arner. 



If we inquire as to the first connection above stated, we 

 may define it briefly in the words of Prof. Phillips, with 

 reference to Megalosaunts, which ''was not a ground-crawler, 

 like the alligator, but moving with free steps, chiefly, if not 

 solely, on the hind limbs, and claiming a curious analogy, if 

 not some degree of affinity, with the ostrich." 1 But the 



1 Woodward in a recent paper refers to a still more curious resemblance 

 of the Dinosaurs to the biped lizard of Australia {Chlatnydosaurus), which 

 runs on its hind limbi--, and even perches on trees. 



N 2 



