128 



NATURE 



{Dec. 12, 1889 



illustrative specimens ; and, indeed, a good collection of 

 typical meteorites is inaccessible to most students. But, 

 further, meteoric irons are very prone to deteriorate, 

 through oxidation, and the perpetuation of the characters 

 of a freshly etched face is thus especially to be desired. 

 The excellence of the photographs is beyond all praise. 

 The details, whether of the chondritic structure or of the 

 Widmanstatten figures, are most beautifully shown. A 

 brief description of the salient features of the sections is 

 furnished with each plate. 



The third work is nominally "a Catalogue of the Vienna 

 Meteorites, but, by reason of the completeness of that 

 collection, is virtually a survey of the petrographical 

 characters of the meteorites of all the known falls. The 

 classification adopted is in the main that suggested by 

 Gustav Rose in 1864, and developed by Tschermak in 

 1872 and 1883. The detailed description and definition 

 of the groups is preceded by a history of the Vienna 

 Collection, and also by a sketch of the various theories 

 which have been proposed relative to the mode of forma- 

 tion of meteorites. As a result of his microscopical 

 researches, Dr. Brezina supports the view that the 

 structural features of meteorites are due to hurried crys- 

 tallization, and not to a slow agglomeration of fragmentary 

 matter. Dr. Brezina adds a chronological list of the 

 meteorites preserved in the known collections, and also a 

 lengthy index of names, synonyms, and localities. The 

 work extends over 126 pages, and is accompanied by four 

 plates. L. F. 



Introduction to Chemical Science. By R. P. Williams 

 A.M., and B. P. Lascelles, M.A., F.C.S. (London : 

 Ginn and Company, 1889.) 



There could hardly be a more concise and well-digested 

 summary of elementary chemical principles and applica- 

 tions than that contained in this work. It is a manual 

 intermediate between the natural philosophy primer and 

 the minute and detailed* text-book, and fills the gap 

 pointed out in the Report on Chemical Teaching of a 

 British Association Committee in 1888. Hence, as an 

 outline of chemical science to be filled up in greater 

 detail from larger works, and as an introductory text- 

 book, this volume will be found exceedingly useful. The 

 experiments described are such as should be performed 

 by everyone beginning the study of chemistry, and would 

 also serve as an excellent introduction to a course of 

 qualitative analysis. In addition to the treatment of 

 metals and non-metals, the work includes chapters on 

 organic chemistry, and others on photographic chemistry, 

 the chemistry of rocks, and electro-chemistry. Indeed, 

 Mr. Williams, the author of the American edition, and the 

 reviser, Mr. Lascelles, may claim to have produced a 

 most comprehensive little work, and one deserving con- 

 siderable commendation. 



The Cradle of the Aryans. By Gerald H. Rendall, M.A. 

 (London : Macmillan and Co., 1889.) 



The question as to the primitive home of the so-called 

 Aryan race has lately excited so much interest that many 

 students must have wished for a short and clear account 

 of the controversies relating to the subject. This is 

 exactly what Prof. Rendall supplies in the present essay, 

 the substance of which was originally communicated to 

 the members of the Liverpool Literary and Philosophical 

 Society. Prof. Rendall accepts Penka's theory that the 

 Aryans were a European people who, at the close of the 

 glacial epoch, followed the ice northwards, and settled in 

 Scandinavia ; and that Scandinavia was the centre from 

 which, at various subsequent periods, groups of the 

 Aryan race were dispersed. All the arguments 

 marshalled by the German writer in favour of this 

 hypothesis are here briefly and effectively stated. The 

 philological part of the case is presented in a more 



scholarlike spirit by Prof. Rendall than by Penka himself, 

 whose rash philological conjectures have prevented a good 

 many people from doing full justice to the weight of his 

 anthropological and ethnological evidence. 



LETTERS TO THE EDITOR. 



[ Tht 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 communications.'\ 



Mr. Cope on the Causes of Variation. 



Mr. E. D. Cope's letter in Nature of November 28 (p. 79) 

 is a fair sample of his writings on biological theory, in so far as 

 I am acquainted with them. 



Mr. Cope proposes to teach Mr. Wallace and others the first 

 principles of both logic and biology. The tone of his letter 

 encourages a similar frankness in reply. Mr. Cope must 

 not take it amiss when he is charged with two of the gravest 

 faults of which a critic can be guilty — namely, complete mis- 

 apprehension of the matter which he is attempting to criti- 

 cize, and no less complete ignorance of the recognized and 

 elementary facts of the branch of science to which that par- 

 ticular matter relates. I do not hesitate to assert that Mr. Cope 

 puts forward an argument which could not possibly be enter- 

 tained by anyone who is acquainted with the most notorious and 

 admitted facts of heredity and variation. I venture to express 

 myself thus emphatically, because it is a matter for sincere re- 

 gret that American biology should at this moment be identified 

 with what is sometimes called "a school of philosophy " which 

 owes its distinction to a deliberate ignoring of the writings of 

 Mr. Darwin. By all means let us have discussion and criticism 

 of Mr. Darwin's conclusions, but let it be understood that those 

 who enter upon such discussion have at any rate an elementary 

 acquaintance with the works of Mr. Darwin himself, if not with 

 those of Weismann and Wallace ; otherwise, much time and 

 much of your valuable space will be wasted. 



That Mr. Cope has not the necessary elementary acquaintance 

 with the admitted facts of heredity and variation will appear 

 from what follows. The discussion in which he has intervened 

 is one as to whether certain structural peculiarities exhibited by 

 flat-fish are due to the transmission to their offspring of a form 

 and position of parts acquired by muscular efforts by the 

 ancestors of flat-fish, or whether these given structural pecu- 

 liarities suddenly appeared in the ancestors of flat-fish as a 

 " congenital variation " having no adaptive relation to any efforts 

 or experiences of a preceding generation, and were advantageous 

 to their possc'^sors, so that the mdividuals thus born were favoured 

 in the struggle for existence, survived to maturity, and trans- 

 mitted their peculiarity to some of their offspring with such 

 intensification as is found experimentally to be the result of 

 breeding from parents both of which possess a given congenital 

 peculiarity. 



The question laised is, in short, whether in this case Lamarck's 

 hypothesis of the transmission of acquired characters is the 

 necessary explanation, or whether the case can be explained by 

 the action of the kno'ivn causes (not hypothetical causes) on 

 which Mr. Darwin founded his theory of the origin of species, 

 viz. the occurrence of congenital variations unrelated to any like 

 variations in parents or ancestors, and the selection and intensi- 

 fication of such variations in subsequent breeding. There has 

 been here no ambiguity — such as unfortunately arises sometimes 

 when like questions are discussed — as to the sense in which the 

 term " acquired characters " is used. It is clear enough that by 

 the "acquired characters" of a parent we do not mean 

 characters congenital in the parent, but expressly exclude them ; 

 it is clear that we refer on the contrary (as did Lamarck) to new 

 characters acquired by the parent as the direct consequence of 

 the action of the environment upon the parental structure, and 

 exhibited by that parent as definite measurable features. 



Now let us consider Mr. Cope's contribution to the discussion. 

 He accuses Mr. Wallace — who is one of those who refuse to 

 adopt Lamarck's gratuitous hypothesis of the transmission of 

 acquired characters — of being guilty of the sin of ' ' non-sequitur " 

 and " paralogism." He then proceeds to make a general state- 

 ment, the truih of which neo-Darvvinians (or post-Darwinians, 

 or anti-Lamarckians), in common with all men, recognize. 



