August 26, 1897] 



NA TURE 



391 



the majority of them are dolichocephalic. The custom 

 is still in full use among the hill tribes who live in the 

 south-east corner of the Algerian plateau, and it is also 

 reported from Montenegro ; there are also traces of it in 

 America. 



The evolution of the saw is ably treated by Dr. Munro, 

 who is careful to point out the permanence of shapes of 

 implements, the early bronze saw being a direct copy of 

 the antecedent flint saw. 



There is no need to further emphasise the fact that 

 Dr. Munro has produced a book which, though designed 

 for the general reader, contains a good deal of new 

 matter, and is a serious contribution to several important 

 aspects of archasology. It seems ungracious to pick out 

 minor points for criticism, but it is desirable to dis- 

 tinguish between " rudimentary " and " vestigial " organs ; 

 those mentioned on p. 21 belong to the latter category. 

 It is a pity to retain the name of " Baton de commande- 

 ment" (pp. 43, 49, 51) for objects which, judging from 

 modern analogues, were in all probability arrow- or 

 javelin-straighteners. A. C. H. 



OUR BOOK SHELF. 

 The Tutorial Trigonometry. (The University Tutorial 



Series.) By William Briggs, M A., and G. H. Bryan, 



F.R.S. Pp. viii -I- 326. (London : W. B. Clive, Univ. 



Corres. Coll. Press, 1897.) 

 In this school-book of three hundred and tvventy-si.x 

 pages the authors have arranged a course on trigono- 

 metry which should be most useful to those studying this 

 subject for the first time. The book may be roughly 

 divided into three portions, dealing first with the tri- 

 gonometry of one angle, then witli that of two or more 

 angles, and, lastly, with logarithms and the trigonometry 

 of triangles. This arrangement seems to work out well, 

 as it allows of the formation of a simple progressive 

 course. The authors rightly lay some stress on the in- 

 sertion of illustrative exercises, and many of these will 

 be found in the text. In the chapter devoted to the tri- 

 gonometric functions of a variable angle special attention 

 has been drawn to the tracing of the curves, so that the 

 reader is here introduced to a method which is of great 

 importance not only in this, but in other subjects. 



I3y a judicious arrangement of different sizes of type 

 the comparative importance of the subject-matter, and 

 also the fundamental formulae, can be easily observed at 

 a glance. Numerous figures and examples are attached 

 to each chapter, the answers being brought together at 

 the end of the book. 



As a course for schools, and for those who are 

 working up the subject by themselves, the book can be 

 recommended. W. J. S. L. 



LETTERS TO THE EDITOR. 



[ The Editor does not hold himself responsible for opinions ex- 

 pressed by his correspondents. Neither can he undertake 

 to return, or to correspond with the writers of rejected 

 manuscripts intended for this or any other part of Nature. 

 No notice is taken of anonymous communiccUions.\ 



"Species or Subspecies.'^ 

 The article by Mr. Lydekker with the above title, in your 

 issue of July 15, deserves some comment. The writer appears 

 to think that the "lumpers" have gained a point; but his 

 attitude, while professing to be a " lumper," shows how much 

 progress the cause of the "splitters" has made in the last few 

 years. It was not formerly a question of "species or sub- 

 species?" at all, but whether what Mr. Lydekker would now 

 call subspecies should be recognised at all in the nomenclature. 

 Dr. Merriam's excellent researches have brought to light a great 

 number of geographical races of our mammals, which were in 



NO. 1452, VOL. 56] 



former years deliberately ignored. It is true that the older 

 naturalists never possessed anything like such good series of 

 specimens as he has had before him, but it is safe to say that 

 even if they had possessed Dr. Merriam's material, they would 

 have despised or overlooked many or most of the facts which 

 could be deduced from it. When species were supposed to have 

 been created separate, it seemed evident that mmor divisions 

 were comparatively of no account, and had nothing to do with 

 real species whatever. At the present time, we recognise the 

 fact that there must be every gradation between individual 

 variations and specific characters, and the whole series of 

 phenomena deserves our attention. The study of subspecies, of 

 variations, and of individuals, are all part of the necessary work 

 of the modern naturalist, and there arises the necessity for a 

 nomenclature applicable to each branch or division of the 

 general subject. 



It is comparatively immaterial whether closely allied forms 

 are called species or subspecies. What is important is that they 

 should be differentiated and named. Now that even " lumpers" 

 are apparently ready to recognise the facts in the nomenclature, 

 "splitters " should consider their convenience as far as may be 

 possible. It is certainly true that while the breaking up of the 

 old generic and specific groups leads to better and clearer ideas 

 of the facts of nature, these facts can be expressed just as well 

 by the use of subgeneric and subspecific names as by the ex- 

 cessive multiplication of " genera " and "species." If, then, it 

 is found that conce,ssions can be made to non-specialists without 

 any real loss of precision and detail, surely they should be 

 made. The result will be to aid the outsider, without really 

 inconveniencing the specialist. 



At the same time, it is quite impossible to so arrange matters 

 that terms of the same rank shall always express groups of 

 equal value. In some genera the groups we must necessarily 

 call species are much less distinct than those of other genera. 

 In Jamaica, for example, as was long ago pointed out by C. B. 

 Adams, the species of land shells are not as distinct as they are 

 in England, and yet if "lumped" would give us "specific" 

 aggregates which would be absurdly large and varied, not com- 

 parable at all with what we commonly understand as species. 

 In other countries, e.g. Italy, we find well-marked species with 

 numerous local subspecies. The three different conditions can 

 be represented as below, the dots representing the specific or 

 subspecific units. ^ 



English land shells :..... 



Jamaica land shells : 



Italian land shells : 



Again, it would be quite absurd to refuse to recognise species 

 which can only be separated by the specialist. There are 

 thousands of perfectly distinct species which an ordinary "lay- 

 man" would confound. Mr. Lydekker seems to realise this 

 when he thinks of the rodents ; for as he well knows, there are 

 not only distinct species, but quite distinct genera of these 

 animals which are popularly confounded, and many cannot even 

 be recognised off"hand by the specialist. No zoologist would 

 have the courage to recommend a classification of the Rodentia, 

 based on the differences observed by ordinary persons, as 

 thus : — 



Genus i. Mouse. 



Species i. House mouse. 



2. Dormouse. 



3. Field mouse. 

 Genus 2. Rat. 



Species i. Brown rat. 



2. Black rat. 



3. Water rat. 



T. D. A. COCKERELL. 



Mesilla, New Mexico, U.S.A., July 31. 



Distant Sounds. 



Is it not possible that the sound of distant firing, mentioned 

 by Mr. C. Mostyn in his letter in Nature (p. 248), may be the 

 same kind of phenomenon as is described in the Annalen der 

 Hydtographie und Maritimen Meteorologie, 1897, p. 160, and is 

 called *' Mistpoeffers"? F. L. Ortt. 



The Hague, August 11, 



1 In each class, a number of smaller dots might be added, if we desired 

 to recognise what are commonly called varieties. Varietal nomenclature 

 is not here considered, but it obviously is a necessity for students of 

 evolution and variation, to whom a variety is often of more interest than 

 a species. In discussing certain clas.ses of cases, e.g. breeds of domestic 

 animals, names are often required for individuals. 



