364 



NATURE 



[August 20, 1903 



specific differences between allied species. While 

 welcoming the restoration of Esox as a generic name 

 for the pike — in consonance with Jordan and Ever- 

 mann's own most recent work— one rather regrets 

 that the author has not reconsidered the reasons which 

 have caused American writers to separate the gray- 

 lings from the Salmonidae as a separate family, and 

 to substitute Stizostedium for the Lucioperca of 

 European authors. 



The reader of this book is immediately struck by 

 the great difference between the American and 

 European fish fauna as viewed by the fisherman ; 

 among fresh-water forms the only Cyprinoid fish con- 

 sidered in any other light than as prospective bait is 

 the introduced Cyprinus carpio, while the place occu- 

 pied in England. by Cyprinoids is taken by numerous 

 species of Percidae and Centrarchidae, the only repre- 

 sentatives of which in our waters are the common perch 

 and the ruff. From the angler's point of view this is 

 no slight gain, especially as some of the Centrarchidae, 

 notably the two species of " Black Bass," attain a 

 large size and rise freely to an artificial fly. Justice 

 is also done to the merits of the grayling, but hardly, 

 we think, to the views of either English anglers or 

 poets respecting it. Among the marine fishes, again, 

 our American friends have very many Serranoid and 

 Scisenoid fishes to set against our bass, and numerous 

 Sparoids where we have but one sea bream that can 

 be considered an " angler's fish," but we find the grey 

 mullets only mentioned as bait for other fish, and no 

 species of Gadoid even mentioned. Mr. Holder is 

 surely right, and the coalfish (the " pollack " of 

 American writers) has not 5'et met with the recognition 

 it deserves as a sporting fish. 



It is, perhaps, hypercritical and unfair to complain 

 of such a matter, but Dr. Henshall's language, 

 especially in dealing with technical descriptions of 

 tackle and gear, is not very intelligible to an English- 

 man, more especially when the great differences be- 

 tween English and American rods and lines are taken 

 into account; it is a little startling to find an eight 

 ounce rod recommended for pike fishing and puzzling 

 to find no details as to the length and build of such a 

 rod. A " chlorinated sea breeze " is apparently a 

 special product of the western Atlantic, like the 

 author's Bahama negro, for whose observations on 

 fishes and their ways all Dr. Henshall's readers will 

 be grateful. 



We are reminded of .a certain traveller's tale about 

 a " mixed bag of wild fowl and hippopotami " when 

 dealing with Mr. Holder's " Big Game Fishes," 

 almost on the same line with Dr. Henshall's work; 

 we pass from the grayling and the perch to the huge 

 Serranoids of the Florida and California reefs, the 

 tarpon, and the pelagic Scombridse, the weights of 

 which are reckoned by the hundredweight, and we 

 pass, too, to descriptions of some of the most exciting 

 fishing man can want. Unfortunately, the English sea 

 fisherman must content himself with smaller game (un- 

 less he chooses to fish for the blue sharks,- which are 

 common enough off our western shores in the late 

 summer), but a work like this should find readers 

 outside the United States; the tunny and the albacore 

 ;>re within reach of British fishermen in the 

 NO. 1764, VOL. 68] 



Mediterranean, the American tarpon has its counter- 

 part in the Indian Ocean, and hugis Serranoids are 

 not confined to American waters. If English or 

 colonial readers should feel encouraged to try their 

 hands at "big game fishing," they will find in Mr. 

 Holder's book all the information they can desire as 

 to the necessary tackle and baits to use, and the kind 

 of place in which to use them, and if Mr. Holder's 

 descriptions of this exciting form of sport do not en- 

 courage them to try their hands at it, we really do 

 not know what will. 



In marked contrast to Dr. Henshall, Mr. Holder 

 gives no specific descriptions of the fish he deals with, 

 and his only attempt at systematic or anatomical de- 

 tail in his introductory chapter is not very happy ; no 

 reason is given for terming the shark " not a true 

 fish," and to dismiss so important a structure from a 

 systematic point of View as a fish's pectoral arch by 

 saying that " many of the corresponding bones among 

 higher animals are seen, as a pectoral arch, scapula, 

 clavicle, ulna, and radius," is neither useful nor 

 accurate. 



The printing and get up of both books is excellent, 

 and both are well illustrated, the one in black and 

 white, the other in colours ; the only fault to be found 

 is that the process blocks of fishes have lost in clear- 

 ness by being printed on rather too rough a paper, and 

 that the figure of Pseuflopleuronectes in Dr. Hen- 

 shall's book is printed upside down; there are also in 

 Mr. Holder's book certain references to a non-existent 

 Fig. 9, which are apparently due to an oversight. 

 The index in each case is very good. L. W. B. 



TECHNICAL PHYSICS. 

 Lehrbuch der technischen Physik. By Prof. Dr. Hans 

 Lorenz. Erster Band. Technische Mechanik 

 Starrer Systeme. Pp. xxiv + 625. (Munich: 

 Oldenbourg, 1902.) 



THIS book is interesting as the work of an engineer 

 who is also a professor in one of the leading 

 universities of Germany, where it is generally conceded 

 that the science and practice of technical education 

 are best understood, and have led in modern times to 

 the most striking practical and commercial develop- 

 ments. The author rightly considers the fundamental 

 principles of mechanics to be the groundwork of all 

 physics, and has chosen mechanics as the subject of 

 his first volume. 



The most striking features of the book, as a whole, 

 are the rigorous mathematical method of treatment 

 adopted, the generality of the principles discussed, and 

 the logical order of the arrangement. In an English 

 '* technical " text-book we should rather expect to find 

 the practical applications in the foreground, and the 

 general mathematical treatment of the principles 

 either absent, or introduced only so far as was neces- 

 sary for purposes of calculation, and not as . the 

 groundwork of the whole arrangement. Owing to the 

 difficulty which many students find in appreciating 

 general mathematical reasoning, we are inclined to 

 make the mathematics as concrete and " practical " 

 as possible, and to restrict it to the immediate appli- 

 cations required for illustrations. No doubt this may 

 produce the best results, on the whole, in the case of 



