NATURE 



529 



THURSDAY, APRIL 6, iJ 



BIRDS. 

 Birds. By A. H. Evans, M.A. Being \'ol. ix. of the 

 Cambridge Natural History. Pp. .\vi + 635. (London : 

 Macmillan and Co., Ltd., 1899.) 



IN getting together the material for this exceedingly 

 elaborate treatise upon birds, Mr, Evans has shown 

 m industry and discrimination which must at once be 

 jbvious to those who have any acquaintance with the 

 jnormous literature of the group. When one thinks of 

 :he many long handbooks upon British birds only, and 

 :he extensive series of large monographs upon special 

 families, it is really a matter for wonder how the author 

 ;an have condensed into rather less than 600 pages an 

 account of the external characters of so huge a number 

 pf existing and extinct genera and species. Mr. Evans 

 las accomplished this difficult task by compressing into 

 IS few words as possible the salient characters, or, in 

 nany cases, character, of the genus or species, and by a 

 rigid economy in the matter of anatomical and "bio- 

 Soraical" fact. This is not mentioned by way of an 

 ntroduction to a criticism of the method adopted by the 

 author. It is obviously desirable that the volumes of the 

 pambridge Natural History should preserve an approxi- 

 Ipate equality in size ; while to give two volumes to birds 

 I — which would be necessary were their structure treated 

 •jf as exhaustively as are the external features — would 

 destroy the perspective of the series. Besides, as Mr. 

 Evans mentions in his preface, several works, such as 

 Dr. Gadow's contribution to Bronn's " Thierreichs,'' 

 Fiirbringer's colossal work, the anatomical sections in 

 (Prof Newton's " Dictionary of Birds," and more recently 

 Still Mr. Beddard's " Structure and Classification of 

 Birds," have rendered it less incumbent upon the author 

 to deal more fully with this branch of ornithology. These 

 considerations have clearly made it difficult for Mr. 

 Evans to decide how much anatomy he should include 

 fn his work. 



tOnly twenty-two pages are devoted to structure, geo- 

 raphical distribution, classification, and migration. It 

 fs unnecessary to point out that to deal with all these 

 Jmportant matters, even in the briefest fashion, twenty- 

 Jtwo pages is not quite adequate. It would have been 

 petter, perhaps, to have allowed the characters of the 

 jfeathers and pterylosis, beak and claw, and colour and 

 'moult, to have absorbed more of this limited space, and 

 jto have slightly expanded the " terminology," with, per- 

 fhaps, an explanatory diagram of the skeleton and of the 

 ;viscera. In the part relating to feathers and external 

 characters generally, that much discussed matter, 

 1" Quintocubitalism," is not even favoured with a mention, 

 let alone a definition. It is unnecessary to point out that 

 jmany other facts of importance in classification share the 

 same neglect. 



b' As to this latter department, Mr. Evans follows Dr. 

 adou's scheme, for which we have a very considerable 

 -jspect. But it really does not matter greatly in a book 

 k)f this kind which of the more reasonable schemes is 

 selected. "Quot homines tot sententife" (with a very 

 idistinct accent on the last word) is a maxim which might 

 NO. 1536, VOL. 59] 



have been created for the science of ornithology. The 

 schemes afloat are so very numerous, and so frequently 

 based not upon anatomical fact but upon opinion. The 

 only consolatory thought is that one of them must be 

 right — so complex are the varied combinations and 

 permutations. 



."Vs to the smaller details of classification, we are not 

 always in accord with Mr. Evans. He places the 

 .African "Shoe bill," Balacniceps, definitely with the 

 herons, in the very same family Ardeidre. The bird has 

 not, it is true, been studied anatomically in anything like 

 an exhaustive fashion ; but enough is known, in our 

 opinion, to militate against this placing of it. Indeed, in 

 his prefatory sketch of the characters of the Arde^e, the 

 author admits that the bird "might well stand alone in a 

 sub-family" opposed to other herons, or that it might 

 even be handed over to the storks. This opinion is, 

 however, abandoned when the actual bird comes to be 

 treated of— a course of action which shows a somewhat 

 unnecessary vacillation. Some ornithologists also would 

 deprecate the isolation of the flamingo, and would 

 definitely term it a stork. But it is not possible to be 

 dogmatic upon the point. In the arrangement of the 

 cuckoos among themselves, Mr. Evans follows Captain 

 Shelley's British Museum Catalogue of the group. It 

 does not appear to us to be requisite to allow so many as 

 six sub-families ; but with the exception of the Neo- 

 mophina;, concerning the merits of which defective 

 anatomical knowledge does not permit of an opinion, the 

 sub-families do represent grades of structural diversity. 

 This, however, is only the case if we refer to each the 

 genera which cluster round that particular genus from 

 which the sub-family takes its name. To place among 

 the Cuculinse, typified by the common cuckoo of this 

 country, the eastern Eudynamis and Scythrops is a very 

 serious offence against the teachings of anatomy. It is 

 to Phoenicophdes that the two genera in question are 

 plainly most nearly allied. The matter is of further 

 importance on account of Prof Fiirbringer's extremely 

 reasonable suggestion that these three genera stand near 

 to the base of the cuckoo tribe ; a view supported — it 

 should be added — by the former existence (as shown by 

 fossil remains) of the genus Phoenicophdes in Europe. 



While Mr. Evans has been unnecessarily liberal in his 

 sub-divisions of the CuculidiC, he has hardly done justice 

 to the structural diversity that exists among the auks. 

 If it was necessary to divide the cuckoos at all — and we 

 are fully in accord with the author in so doing — it is at 

 least equally advantageous to sub-divide the not more 

 homogeneous family of the Alcida;. The genera Lunda 

 and F?-atercida are connected by closer bonds than 

 either is with Uria and Alca, while the two latter form 

 an alliance which is equally patent to the anatomist. 



It has been hinted that Mr. Evans is somewhat sparing 

 of anatomical fact in this volume. At the same time 

 he by no means ignores in places anatomical characters. 

 For the most part we find that these characters are 

 quite accurately described. But here and there is a 

 slip. For instance, the Anseriformes are defined by the 

 possession of two pairs of sterno-tracheal muscles, " a 

 marked point of distinction from other Carinate birds." 

 It is unquestionably true that this is a characteristic 

 feature of the large group of ducks, geese, swans, and 



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