xv CLASSIFICATION 381 



tinguish real marks of relationship from what is due 

 merely to similarity of life and circumstances, or, to 

 put it technically, to depend upon homologies and not 

 upon mere analogies. The application of the true 

 principles has caused the Horned Screamer, in spite 

 of his arboreal habits, to be put near the Goose. In 

 spite of his way of life and his long legs, which suggest 

 that we should class him with wading birds, the 

 Flamingo is allied to the Duck, as his webbed feet 

 and his beak proclaim. Not only must structural and 

 not functional characters, or mere habits, be studied 

 for purposes of classification, but the concurrent 

 testimony of a number of characters must in every 

 case decide to which family a bird belongs. In 

 botanical classification Linnaeus made the mistake of 

 taking into consideration nothing but the number of 

 stamens. According to his system a wall-flower 

 and a lily, a campanula and a dandelion, a buttercup 

 and a rose, would belong to the same orders. The 

 natural system produces results which may seem 

 strange {e.g. the buttercup is put in the same order 

 as the Traveller's Joy), but which will bear investiga- 

 tion. And in the same way the scientific classification 

 of birds, startling as its results may often appear, yet 

 gains more and more adherents as true principles 

 come to be recognised. But, though the right method 

 has now been adopted, the difficulties have not 

 vanished. Many systems have recently appeared 

 which differ in very important particulars, though 

 the constant tendency is towards the narrowing of 

 the divergencies. In Mr. Howard Saunders' Manual 

 of British Birds the orders are not in all cases the 



