30 CRACID^: AND MEGAPODID^, [CH. I 



perdix (one species only), from the Eocene of France, 

 which is said to present affinities with Numida and 

 Meleagris, i.e. with African and American forms. The 

 facts which have so far been enumerated enable us to 

 draw some interesting conclusions ; the first is indis- 

 putable ; each of the great divisions of the globe is 

 tenanted by a special group of Gallinaceous birds, which 

 is with the exception of the nearly cosmopolite Tetraonidse, 

 confined to that particular region. There are some 

 reasons for considering that the cosmopolitan Tetraonidse 

 are of a less ancient stock than the restricted Cracidas and 

 Megapodidse. There is a closer structural connection 

 between the Gallinaceous birds of the three great con- 

 tinents of Europe, Africa and Asia, than between any one 

 of them and the Gallinaceous inhabitants of South 

 America or remote Australia. The two latter regions, 

 being truly the ends of the earth, are populated by the 

 two most ancient types of Gallinaceous bird, which how- 

 ever are not very closely allied. 



In a very tentative way we may point out another 

 possible conclusion. We may presume that the earth 

 was possessed, as regards Gallinaceous birds, by an ancient 

 stock of which the Cracidse and Megapodidae are the only 

 survivors; later on, from the ancient stock, arose other 

 families which increased and multiplied so much as to 

 drive their forerunners into the more remote corners, 

 where an inroad of the sea preserved them from further 

 competition ; as the remnants of the more ancient 

 race came thus to be widely separated and exposed to 

 divergent conditions they would naturally get to be more 



