STRUCTURAL CHARACTERS 559 



There seems to be an irresistible desire on the part of amateurs in the task of classification 

 so to arrange the various groups of birds that an apparently easy transition from one to the 

 other is secured. Thus the Passeriformes are linked on to the Coraciiformes by making the 

 former end with the Swallows and the latter begin with the Swifts. The Owls are made to 

 provide the transition to the Accipitres. The Gulls are placed in close proximity to the 

 Petrels, and we are invited to pass from the Auks to the Grebes and 1'ivcrs, and so on. 



Tliis looks simple and natural enough. But when we come to inquire into the reason, 

 or rather the evidence for this arrangement, we find no satisfactory answer forthcoming. As 

 a matter of fact, all such systems are founded on the fallacy that superficial likeness is an 

 indication of affinity. Nothing could be further from the truth. The likenesses which these 

 " links " possess to the members on either side of the chain are purely imaginary. And this 

 can be immediately proved by an appeal to anatomy, an appeal which those who frame such 

 schemes are unable to make. 



It is not always so easy to understand the vagaries of the systematists who pursue these 

 methods. What reason, to quote actual and recent examples, can be assigned for placing 

 the goldcrested- wren with the Titmice? Or for placing all the surface-feeding ducks in the 

 genus Anas save only the shoveler and the pintail, each of which represents a genus in 

 itself? Or why, again, is the goldeneye included in the genus Nyroca, which is made to 

 include all the diving ducks save the Eiders, Scoters, and Mergansers ? 



The classification adopted in these volumes, I am painfully aware, leaves much to be 

 desired. But it would have been impossible to hold back their publication till the tangled 

 skein which this theme presents had been unravelled. In many cases the information at my 

 disposal has been most unsatisfactory ; but the facts I needed were such as demanded more 

 leisure for original investigation than I am likely to possess for a long while to come. 



In the matter of plumage-changes, it might be imagined I had every opportunity of study 

 from the vast collections in the British Museum. But this is by no means true. Much, very 

 much, needs yet to be done to fill in gaps in the series possessed by the Museum. These 

 Mr. Ogilvie-Grant, since he assumed the reins of government, is endeavouring to fill up as 

 speedily as possible, but he has much to accomplish before he achieves his end. Male, female, 

 and young, in every season of the year, and from many localities, must be obtained before we 

 are able to give a complete account of the sequences of plumages of a species. 



For the sake of the field-naturalist who has to rely on standard works of reference, I had 

 to endeavour to justify as many genera as I could, though it went much against my inclination 

 to do so, and in some cases I have had to abandon the attempt. 



The diagnoses of Orders and Suborders and Families are of necessity based on internal 

 structural characters. This must always be so if our classification is to represent pedigree. 

 Blood relationship, descent, must be the key-note of all our endeavours at classification, and 

 this relationship can only be discovered by dissection. In using this unfamiliar material, 

 however, I have drawn as little on anatomy as I possibly could. Muscles I have almost entirely 

 left out of account, such, for example, as the shoulder and thigh muscles and the plantar tendons. 



The field-ornithologist is little, if at all, concerned with anatomical details ; his work, an 

 essential and all-important side of ornithology, is concerned rather with birds as living things ; 

 and commonly also with their external characters after death. But here he touches on the 

 border-line of anatomy. And no field-naturalist who concerns himself with plumage sequences 

 can hope to do really first class work who does not master at any rate the rudiments of 

 pterylosis and feather structure. He should do more. But for this obstinate, wilful neglect, 

 our knowledge of our native birds would be far more thorough than it is. There are some who 

 assure us that the study of British Birds is " played out " that we have nothing new to learn 

 about them. If the pages of these volumes have shown anything, they have shown that our 

 knowledge of our native avifauna is very far indeed from being complete. But they should 



