OSTEOLOGY OF THE SOLITAIRE. 355 



gamous. Leguat, therefore, may easily have been mistaken in 

 his opinion, even setting aside his evident leaning in the matter. 

 The notion of PezopJurps having been polygamous was before 

 entertained by one of the authors, and arises from a consideration 

 of the great difference in the size of the two sexes, which, in 

 birds, is generally accompanied by polygamous habits ; but the 

 question is now not likely to be solved. 



The amount of variability which every bone of the skeleton of 

 this species presents, warrants the conclusion that as much was 

 displayed in those parts of its structure which have perished, 

 letting alone Leguat's direct evidence as to the individual 

 difference in the plumage of the females. 



"If such a process, therefore, as has been teruied 'natural 

 selection', or 'survival of the fittest', exists, there would have 

 been abundant room for it to operate; and there having been 

 only one species of Pewphaps might at first sight seem an argument 

 against the belief in such process. . . ." 



IMessrs. Newton proceed from arguments to show that "a 

 believer in Darwin's theory would be inclined to predicate that, 

 when a small oceanic island like Eodriguez is found tenanted by 

 a sinr/le species subject to great individual variability, it would 

 be just under such circumstances that the greatest amount of 

 variability would be certain to occur. .In its original state, 

 attacked by no enemies, the increase of the species would only 

 be dependent on the supply of food, which, one year with another, 

 would not vary very much, and the form would continue without 

 any predisposing cause to change, and thus no advantage would be 

 taken of the variability of structure presented by its individuals. 



" On the other hand, we may reflect on what certainly has taken 

 place. Of the other terrestrial members of the avifauna of 

 Rodriguez, but few now remain. A small Finch and a AVarbler, 

 both endemic, are the only two land-birds of its original fauna 

 now known to exist. The Guinea-fowl and Love-bird have, in all 

 probability, been introduced from Madagascar ; but the Parrots 

 and Pigeons, of u hich Leguat speaks, have vanished. The remains 

 of one of the first, and the description of the last, leave little room 

 to doubt but they also were closely allied to the forms found iu 



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