NA TURE 



62! 



THURSDAY, OCTOBER 26, 1905. 



THE STUDY OF FISHES. 

 A Guide to the Study of Fishes. By David Starr 

 Jordan. Vol. i., pp. xxvi + 623; vol. ii., pp. xxii + 

 599; with coloured frontispieces and 427 illustra- 

 tions. (New York : H. Holt and Co., 1905.) Price 

 40X. 



THIS beautiful work naturally invites comparison 

 with the recently published seventh volume of 

 the "Cambridge Natural History." Both actually 

 cover the same ground, since both contain also an 

 account of those invertebrates which, like Balano- 

 glossus, Tunicates, and Amphioxus, claim the 

 ambitious honour of a more or less direct ancestral 

 position to the fishes. 



It has been objected that the anatomical treatment, 

 although good, exact, and up to date, takes too much 

 space of the Cambridge volume, to the detriment of 

 those more oecological questions which are of more 

 general interest, and are, after all, as important as 

 the structural detail, because they make up the life 

 of the fish. The systematic account of the Teleostei, 

 containing Boulenger's new classification, forms the 

 main feature, rather stern, only here and there re- 

 lieved by some interesting and little known inform- 

 ation about habits, showing that want of space, not 

 disinclination, has guided the author. 



The author, who is president of the young and 

 vigorous Universit}' at Palo Alto, in beautiful and 

 exhilarating California, proceeds nominally upon the 

 same plan, but its execution is totally different. 

 With him the fish is alive, even the fossil. 

 Having travelled much, he has fished with the 

 Japanese, trawled in the vast Pacific, and the huge 

 continent of North America is his special domain. 

 He has collected much, and has observed more " in 

 the good company of the woods and brooks." 



" The man who kills all the trout he can, to boast 

 of his skill or fortune, is technically known as a 

 trout-hog. Ethically it is better to lie about your 

 great catches of fine fishes than to make them. For 

 most anglers, also, it is more easy." 



The first volume begins with a popular account of 

 the life of the long-eared sunfish. What is a fish? 

 What is it like, and so unlike, to everything else? 

 How does it breathe, see, move, adapt its coloration, 

 and how does it breed? After we have caught it, and 

 observed it in an aquarium, it is dissected, and the 

 student is introduced to the morphology from a 

 general point of view. The account which follows is 

 neither stiff nor anything like exhaustive, but in about 

 100 pages enough is said to help the intending 

 ichthyologist to an appreciation of the taxonomic 

 importance of ichthyotomy and its salient problems. 

 Many of our fundamental questions of vertebrate 

 morphology find their solution in the fishes. The 

 author devotes a vi'hole and long chapter to the 

 morphology of the fins, with a clear exposition of the 

 vexed controversy whether the pectoral limb has arisen 

 from a problematic lateral skin fold or from an 

 organ like a gillarch, which already did exist, and 

 NO. 1878, VOL. 72] 



required but a slight change of shape and function. 

 The organs of respiration lead to a summary of the 

 present state of our knowledge concerning air-bladder 

 and lungs ; the other organic systems follow suit. 

 What the author has to tell us are all points which, 

 although they can be studied elsewhere, could not 

 well be omitted from such a work. 



Not so chapters x. to xx. Postembryonic develop- 

 ment, with the often most peculiar larval forms ; 

 instincts, habits and adaptations afford a rich field 

 of observation, graphically described, with admirable 

 illustrations. Witness the photograph of the. tens of 

 thousands of fishes which, having run up-stream to 

 spawn after a rain, are left stranded by the falling 

 water. 



Protection by the spines, by the poisonous nature 

 of the flesh, electric batteries, luminous organs, quaint 

 nursing habits, are, of course, the stock in trade of 

 any book on fishes. The angling apparatus of 

 Lophius is such a feature, but it is not often that it 

 is treated as follows ; — 



" In the large group of angler-fishes the first spine 

 of the dorsal fin is modified into a sort of bait to 

 attract smaller fishes into the spacious mouth below. 

 This structure is typical in Lophius, where the fleshy 

 tip of this spine hangs over the great mouth, the 

 huge fish lying at the bottom apparently inanimate 

 as a stone. In other related fishes this spine has 

 different forms, being often reduced to a vestige, of 

 little value as a lure, but retained in accordance with 

 the law of heredity. In a deep-sea angler the bait is 

 enlarged, provided with fleshy streamers and a 

 luminous body which serves to attract small fishes 

 in the depths. The forms and uses of this spine in 

 this group constitute a very suggestive chapter in the 

 study of specialisation and ultimate degradation, 

 when the typical function is not needed or becomes 

 ineffective." 



This is truly observation and reflection combined, 

 and the rendering of it is that of a thorough 

 evolutionist who is in sympathy with his favourite 

 class of creatures. 



The colour of fishes is another fertile field, with 

 sexual, nuptial, and protective changes. Perhaps in 

 order to curb the ardour of those who see some special 

 good or purpose in every pattern or colour, we are 

 told that the brilliantly coloured fishes of the tropical 

 coral reefs have no need of protective coloration. 



The chapters on geographical distribution might 

 well form an essay by themselves, since in them are 

 interwoven lessons of natural selection, the effects of 

 temperature, agencies of oceanic currents, the effects 

 of the direction of coast-lines, and last, not least, 

 the separation of faunas by isthmus barriers, notably 

 those of Suez and Panama. Their far-reaching results 

 are explained by an analysis of the Japanese fish- 

 fauna in comparison with that of the Mediterranean 

 and Central American waters. But whilst the 

 methods of marine distribution and their final results 

 are relatively simple, the fresh-water fishes provide 

 stiffer problems, and some forty pages are therefore 

 devoted to the ways and means, successes and 

 failures, as exemplified in detail by the fauna of the 

 North American continent. This makes fine and 

 admirable reading, but it also shows the value, scien- 



D D 



