ORDER ACCIPITRES. 157 



species, these spots and streaks undergo so great a change in 

 the course of time, that scarcely any vestige remains of them 

 in the old males, which has often occasioned an erroneous dis- 

 tinction of species. Thus we find the vulture of Malta, passing 

 from brown to white, becomes the vulture of Norway and the 

 little vulture of Buffon : the monachus ends by being the black 

 vulture, quitting its gray and brown plumage to assume a very 

 dark brown. The fulvous vulture, reddish in its youth, becomes 

 successively gray, ashen, and of a uniform gray white in 

 advanced age. We find the osprey become the gray-headed, 

 and, in old age, the white-headed pygargus. This has been 

 contradicted, it is true. It has been advanced that the white- 

 headed pygargus is a distinct species from the gray, which last 

 is found only in North America and the most northern parts of 

 Europe. But M. Vieillot declares that he has seen the osprey, 

 and the gray and white-headed pygargus, in the United States ; 

 all three of which he considers, as in Europe, to belong to the 

 same species. Another fact, cited by the same ornithologist, is 

 that a white-headed pygargus in the menagerie of the " Jardin 

 du Roi" was taken in France, and on its arrival there resem- 

 bled the osprey extremely. The plumage of the pygargus 

 passes more quickly to white on the head in the northern 

 regions of both continents. 



The birds of prey are much more numerous, in species, in 

 Paraguay and the neighbouring countries, than in the rest of 

 tlie world, according to M. d'Azara. There is one species of 

 them to nine of other birds, Avhile in the old world there is but 

 one to fifteen. The birds of prey described by this naturalist 

 are not quite so ferocious or carnivorous as others, for the 

 majority of them live on insects, frogs, toads, serpents, &c., 

 rather than on quadrupeds and other birds. 



The first division of our author, on which we shall offer a 

 few remarks, is that of the Vultures. But it is by no means 

 our intention here, or in any other part of our supplementary 

 observations, to notice all the species which have been enume- 



