338 



NA TURE 



[August 12, 1897 



eighty or ninety species of British marine food-fishes are 

 dealt with in their volume. 



"Then (in 1883) the life-history of not a single British 

 marine food-fish was known, at least from observations 

 in our country. In the present work between eighty and 

 ninety species are dealt with, the majority of the important 

 forms more or less exhaustively." 



This is obviously an error. From some points of view, 

 it may be convenient to regard every marine fish as a 

 *' food-fish." The economic importance of observations 

 on the stickleback is increased if we reckon that pug- 

 nacious mite as a "food-fish," and a list of contributions 

 to the solution of practical fishery problems is, by such 

 reckoning, enlarged to imposing dimensions. But in the 

 ordinary sense of the term " food-fish," so many as 

 eighty do not exist in British waters, and only a 

 fractional part of these have any economic importance. 

 The word "exhaustively" is also open to some objection ; 

 but as we are given the choice of "more" or "less" in 

 relation to it, we can not actually disagree with the 

 authors' statement. 



The preface seems also to me to be deficient in that, 

 whilst the authors there make a profession of acknow- 

 ledging the sources from which they have gained 

 information, and of recognising the activity of other 

 laboratories and other workers than those to be met 

 with at St. Andrews, yet in the most marked manner 

 all allusion to the Plymouth Laboratory and the publica- 

 tions of the Marine Biological Association is omitted. 

 After making a eulogistic statement as to the importance 

 of the work done at the St. Andrews Marine Laboratory, 

 followed by a list of those who have worked there, the 

 authors at once proceed to say : 



" For many interesting papers connected with the 

 Fisheries we have to thank our fellow-workers in the 

 maritime States of the continent, in America, and the 

 British Colonies." 



The suggestion to an uninformed reader is that the 

 only work on these subjects, done elsewhere than " in the 

 maritime States of the continent, m America, and the 

 British Colonies," has been done at St. Andrews. This 

 is very far, indeed, from a truthful suggestion, and is 

 surely due to some oversight on the part of Prof. 

 Mcintosh, who has served on the Council of the Marine 

 Biological Association, and is acquainted with the 

 researches carried out on the west coast of Ireland, at 

 Plymouth, in the North Sea, in the Clyde by a host of 

 able investigators remote from his charming little labora- 

 tory. Seeing that the authors' book owes a large and 

 important part of its value to the frequent quotations 

 from the Journal of the Marine Biological Association, 

 and the work carried on by Mr. Cunningham at the Ply- 

 mouth Laboratory, and Mr. Holt at Grimsby, it would 

 have been more gracious on their part to have given 

 credit to the Plymouth Laboratory, and the naturalists 

 working in connection with it, when they professed to 

 make acknowledgments to colleagues and predecessors. 

 The work of these investigators, as also of Green, 

 Bateson, Heape and others is made use of, but often 

 without citation of the author's name, and in almost all 

 cases without reference to the original place of publica- 

 tion ; so that as a guide to the literature of the subject, 

 the book fails. The index is constructed in a very 

 .NO. 1450, VOL. 56] 



startling way. One looks up " Cunningham ■\ in order to 

 ascertain how often, and in what terms, his work has 

 been quoted by the authors, and this is what one finds — 

 "Cunningham, J. T., 18, 92, &c." The use of " &c." as 

 a page-reference in an index is altogether new. It does 

 not seem to me to be a real improvement upon the old 

 plan of giving the numbers of the pages to which re- 

 ference is desired. It is, however, I am sorry to say, 

 indicative of the spirit in which British cotemporary 

 investigators have been treated by Prof. Mcintosh and 

 Mr. Masterman. 



In a recent review, written by a St. Andrews man, 

 Mr. Cunningham was rebuked for not having referred to 

 Prof. Mcintosh and the St. Andrews Laboratory with 

 sufficient frequency in his work on " British Marketable 

 Fishes." It seems that the treatment of the Plymouth 

 Laboratory and Journal of the Marine Biological 

 Association and its staff as "&c.," is the retort of St. 

 Andrews. I am sorry, because I have a personal interest 

 in, and regard for both, the Northern and the Southern 

 institution. It is to be hoped that those who have the 

 disposal of fishery appointments at home and abroad 

 will read the productions emanating both from PI ymouth 

 and from St. Andrews, so as to be under no illusion as 

 to the non-existence of either. E. Ray Lankester. 



THE CALCULUS FOR ENGINEERS. 

 The Calculus for Engineers. By John Perry, F.R.S. 

 Pp. vi -h 378. (London and New York : Arnold, 1897,) 



HERE is a new departure ; a book on the calculus 

 written without any reference to the examination 

 room, solely with the object of teaching the engineer, first 

 that he is already in possession of the fundamental ideas 

 of the calculus, and accustomed to use them, then that 

 these ideas can be easily put into exact mathematical 

 formulas, and ultimately that the advantages of the 

 formal calculus thus obtained are great indeed, and can 

 be reaped without an enormous amount of previous 

 knowledge. 



Prof. Perry does not treat the calculus as something 

 which requires a number of altogether new notions and a 

 great deal of subtle reasonings to be instilled into the 

 mind of the reader. With the instinct of a true teacher, 

 he sets himself to develop notions already in the mind 

 of the learner, and by constant reference to concrete 

 cases leads up to the mathematical ideas of the differ- 

 ential-coefficient and the integral. The former is not 

 defined, as in the ordinary text-books, for any function 

 y —f{x\ but the simplest function _y = a -t- /Jjr is con- 

 sidered and plotted out. In fact. Chapter i. begins with 

 the plotting of curves on squared paper, analytical conies 

 or coordinate geometry not being supposed known. It 

 is found that all such equations which have the same 

 value for b have the same slope. Hence b is called the 

 slope of the line, and this is denoted by dyjdx. This is 

 followed by exercises on the straight line, familiarising 

 the reader with the notion of slope, and showing how 

 former knowledge of algebra and trigonometry comes in. 



Only after this is the differential-coefficient for the 

 simple case treated generally by giving x and y small 

 increments, and therefrom calculating dyjdx. This pro- 

 cess of starting with the concrete, and of considering the 



