79 [Vol. XXXV. 



genera have been separated on that account, and that its 

 importance has been a great deal overrated. I do not mean 

 to say that colour-pattern should be neglected ; it is often 

 a valuable sign-post and guide indicating to which genus 

 a bird should be assigned, but it can never be a test and a 

 final proof of whether it ought to belong here or there. Let 

 me give you a few examples : — 



Look at Oriolus forsteni and Philemon subcorniculatus on 

 Ceram, and at Oriolus bouruensis and Philemon moluccensis 

 on Burn. In each case the Oriole and Honey-eater are 

 absolutely indistinguishable in colour, almost to the minutest 

 detail, only the hill and foot, and the anatomy too, of course, 

 being different, because these similarly coloured birds belong 

 to different families. These two cases are, as is well known, 

 the classical instances of mimicry among birds, since they 

 were so cleverly expounded by Wallace ; as a fact, they are 

 not mimetic, but the results of independent gradual develop- 

 ment, and 1 believe they would have had the same coloration 

 if on each island only the Oriole or the Philemon had been 

 found (see ' Novitates Zoologicae,^ xxi. pp. 395-iOOj. I may 

 also remind you of the similarity in coloration of the American 

 Pachy Sylvia and Palsearctic Phyiloscopus, of various white- 

 coloured Arctic birds, which are very distantly related to 

 each other, of various species of the genera Accipiter and 

 Astur, as generally accepted, in the islands of the Eastern 

 Archipelago, which are of the same coloration and yet very 

 different. The weakness of colour-pattern as a generic 

 character is also shown by the different coloration of adult 

 and young in ever so many instances, where Ave have the 

 young birds quite differently marked from the adults — 

 for instance, among Accipitres, where many species are 

 barred when adult, and striped when young, or among 

 Robins, E-edstarts, Nightingales, Flycatchers, and Thrushes, 

 where only the young are spotted. Think also of the species 

 of (Euanthe [Saxicola), where the young of some species 

 are spotted, others not, and yet they are united into one 

 genus, and I trust they will not be torn asunder on account 

 of these juvenile propensities. 



