2 5 8 



NA TURE 



\_Ju/y 10, 1884 



the common resident birds of their respective countries. Trie 

 -value of such collections as that which Mr. Seebohm is making 

 cannot be over-estimated. 



I have exhibited to-day three distinct illustrations of birds 

 from the Old World where trinomial nomenclature might 

 be employed. In the case of the Goshawks, the Sc<>ps 

 Owls, and the Crows, I am not yet certain that my way 

 of treating them in the "Catalogue'' as sub-species is 

 not as advantageous as the employment of trinomials. But 

 in the case of the Long-tailed Titmice the circumstances 

 seem t>> me different, and the adoption of trinomial nomencla- 

 ture would be a positive advantage, because Aeredula caudata 

 undoubtedly mixes with A. rosea in the Rhine provinces and 

 other parts of Europe; therefore in England, where the rosea 

 strain is apparently pure and unmixed, it is advantageous to 

 speak of the bird as Acredula caudata rosea, because such a 

 name clearly conveys the idea that .-/. rosea is a form of A. cau- 

 data, with which it is connected by intermediate forms else- 

 where. A . caudata irbii would also express the relationship of 

 the South European bird, and A. caudata trivirgata the Japanese 

 form. 



The case of the Wagtails is not so clear, because we do not 

 yet seem to have sufficient material to work upon. Even here 

 some of the races might be fairly expressed by the employment 

 of trinomials, as Motacitta flava dubia for the Siberian and 

 Indian race of .1/. fiiva. J/, viridis being a form without an 

 eyebrow, would have a Mediterranean race, .)/. viridis cinereo- 

 capilla, while M. meIanoce/>ha/ahas at least one race, M. melana- 

 cfphala kalcniczenkii, unless the la-.t-n.mied ultimately proves to 

 be a hybrid. 



I may say in conclusion that the great difficulty which I 

 perceive in the adoption of trinomial nomenclature, both at 

 home and abroad, lies in the fact that it will open the door to a 

 multiplication of species, or races, founded on insufficient ma- 

 terials, and bestowed by authors who have not sufficient experi- 

 ence of the difficulties of the subject ; but I cannot conceal from 

 myself that the code of nomenclature proposed by the British 

 Association and followed by most of us scarcely accounts for the 

 treatment of facts as they have been developed in zoological 

 science since the promulgation of that code, and that before 

 long it will be the duty <>l British zoologists to attempt its modi- 

 fication. 



Mr. Henry Seebohm read the following paper: — The ques- 

 tion of a binomial or trinomial nomenclature is not a very 

 simple one. So long as ornithologists were under the delusion 

 that all species were separated from each other by a hard and 

 fast line, the binomial system of nomenclature was sufficient. 

 Now that we know that many forms which have been regarded 

 as species are connected by intermediate links with each other, 

 and that many species present important local variations which 

 cannot be ignored, we are obliged to admit the existence of sub- 

 species as well as species. There can be no doubt that the too 

 tardy recognition by European ornithologists of what might not 

 unreasonably lie regarded as the most important fact in orni- 

 thology discovered during the present century has been very 

 largely due to a pedantic adherence to a binomial system of 

 nomenclature. Now that we have emancipated ourselves from 

 the fetters with which our predecessors, with the best intentions 

 in the world, cramped our ideas, the question arises, how shall 

 we recognise in our nomenclature the existence of sub-specific 

 forms; by a word, or by a sentence? The ornithologists of 

 America think that a system of trinomial nomenclature will 

 answer the purpose. They have come to the conclusion that the 

 insertion of a third link in t lie chain which binds us will give our 

 ideas scope enough. Their theory is that the judicious orni- 

 thologist will be able to select from the infinite number of steps 

 which form the series of intermediate races which lie between 

 two intergrading species, one, two, three, or even in some cases 

 more local or climatic races which are worthy of being dignified 

 by a name. This theory is on the face of it somewhat illogical. 

 It credits ornithologists with an amount of discretion which 

 their past history does not justify, and totally ignores the in- 

 ordinate desire to introduce new names which is unfortunately 

 too conspicuous in most il not in all ornithological writers, cul- 

 minating in the absurdities of a Brehm. That ornithology 

 should be preserved from being Brehmised must be the devout 

 prayer of every well-wisher of the science. On the other hand, 

 the recognition of sub-species by a sentence would be to revert 

 to the customs of the pne-Einnean dark ages of nomenclature, a 

 retrograde step from which all zoologists would instinctively 

 shrink. Members of the British Ornithologists' Union are 



probably all prepared to admit that a medium course is safest at 

 least for an Ibis (medio tutissimus ibis), and, with a very slight 

 modification, I for one am prepared to adopt the American 

 system in spite of its dangers. If no paths are to be trodden 

 in which the indiscreet may err, there i> an end at once of all 

 progress. 



To point out the modifications which I propose to introduce 

 into the American system of nomenclature to change it from an 

 empirical system to a logical or scientific system, I will take 

 as an example the Common Nuthatch (Sit a turop&a) and show 

 how the nomenclature of its various races may be made 

 exhaustive, so that the temptation to introduce new names, 

 which appears to be irresistible to the indiscreet ornithologist, 

 may be minimised. 



Sit/a uralensis, with white under parts, is found in Siberia ; 

 Sitta cassia, with chestnut under parts, is found in England ; in- 

 termediate forms connecting these species together are found in 

 the Baltic provinces. What can be more simple than to call the 

 intermediate forms by both names, Sitta ccesia-uralends ? But 

 there is a third species which turns up in China, Sitta sinensis, 

 and which is also connected with Sitta uralemis by intermediate 

 forms. Never mind ; they too can be called by both names, 

 and our series of Nuthatches runs geographically in an unbroken 

 series : — 



Sitta ccssii, 

 Sit'a casia-uralensis, 

 Sitta uralensis, 

 Sitta ura/ens 's-sinensis, 

 Sitta sinensis. 

 So far so good; but, unfortunately, two more complications 

 arise. Besides the series running south-west into S. cassia, and 

 that running south-east into S. sinensis, two other series run 

 from the central form S. uralensis, one running due west and 

 then round by the Baltic into the Scandinavian S. europcra (a 

 larger bird, and somewhat darker on the under parts), and a 

 second running due east and then round the Sea of Okotsk into 

 the Kamehatkan .S'. atbifrons (a bird much paler on the head, 

 which shades into white on the forehead), so that it is necessary 

 to add four more names to the list, which will stand as under : — 

 Sitta cassia is found in Britain, South- West and South Europe, 

 and Asia Minor. It is medium in size, but extreme in the dark- 

 ness of the chestnut of the under parts. 



Sitta cassia-uralensis (with a hyphen between the two specific 

 names) represents all the forms intermediate between South 

 European and Siberian examples, which occur in Denmark, 

 Pomerania, the Baltic provinces of Russia, Poland, and the 

 Crimea. 



Sitta europaa is the Scandinavian form, and represents the 

 extreme of size, whilst in colour it is intermediate between the 

 fii ins found in the Baltic provinces of Russia and Central 

 si!.- ria. 



Sit a ruropcva-uralensis comprises all the intermediate forms in 

 Russia which connect the Scandinavian with the Central 

 Siberian forms. 



Sitta uralensis is found in the valleys of the Ob, the Yenesci, 

 and the Lena, and combines the small size characteristic of the 

 various Asiatic sub-species of Nuthatch with the dark upper 

 parts of the sub-tropical forms, whilst the under parts are nearly 

 as white as in the Kamehatkan form. 



Sitta uralensis-albifrons may be applied to all those intermediate 

 forms found in East Siberia and the north islands of Japan 

 which are not quite so pale on the upper parts as the Kamehatkan 

 form. 



Sitta albifrons is found in Kamchatka, and represents the 

 extreme form so far as whiteness of the forehead and under parts 

 is concerned. 



Sitta uralensis-sinmsis may be applied to the series of forms 

 found in the valley of the Amoor, the island of Askold, and the 

 main island of Japan. They are intermediate in colour between 

 the Central Siberian and Chinese forms, and are scarcely to be 

 distinguished from the Baltic province forms. 



Sitta sinensis is found in China, and only differs from the 

 British form in being slightly smaller and in not having quite so 

 much dark chestnut on the flanks. 



I have purposely chosen a complicated case in order to show 

 the capabilities of the system, which, if the specific name of 

 enre/ua is always repeated after the generic name ofSitta, becomes 

 a compromise between that adopted by the Americans and that 

 which I imperfectly carried out in the fifth volume of the "Cata 

 logue of Birds in the British Museum," and which was originally 

 suggested to me by a conversation with Mr. Salvin. Il has at 



