January 9, 1902 J 



NA TURE 



2 19 



not free from trepidation, an instance where we think 

 Mr. Wells has been caught napping. When the cavorite 

 blinds are closed and the sphere starts on its journey, he 

 ■describes the curious eftects of the absence of external 

 gravitational attraction — all the material occupants of the 

 sphere slowly collect in the interior by their mutual 

 attractions, and there is no "up" or "down." Then a 

 window is opened towards the moon and promptly every- 

 thing gravitates towards the moon — the direction towards 

 the moon is rfcwwwards, though the attraction is slight. 

 Surely this is a slip ? With bodies moving freely in space 

 only the differenliixt attraction would be felt, and this 

 would be negligible compared with the mutual attraction 

 of the occupants of the sphere. Even if it were not so 

 small it could not act in the manner specified ; its 

 tendency would be to separate bodies (as in the case of 

 the tides), not to bring them together, and thus a man 

 near a "floor" would not fall towards it but would rise 

 from it. But Mr. Wells is so wonderfully careful in 

 general that we make this criticism with far less confi- 

 dence than we should have felt in another case ; we have 

 an uneasy feeling that he may dexterously transfer the 

 supposed slip from his account to ours. 



A POPULAR WORK ON FISHES. 

 The Story of Fish Life. By W. P. Pycraft. Pp. 210. 

 (London : G. Newnes, Ltd., 1901.) Price is. 



T HI. Shook, which is one of the shilling series pub- 

 lished by Messrs. Newnes, is divided into fourteen 

 chapters and illustrated by seventeen te.xt figures and a 

 frontispiece. Its contents are generally interesting and 

 well arranged, but there is recognisable throughout its 

 pages a leaning towards the racy and sensationally at- 

 tractive, as, for example, in the method of dealing with 

 the habits of the sword-fish and the feeding process 

 generally. The mode of treatment is mainly physiological, 

 the consideration of fuoction preponderating over that of 

 structure and development. Migration and "transforma- 

 tion" are in turn dealt with, the latter with a com- 

 mendable emphasis of the part played in Nature's 

 operations by "substitution." 



Much attention is given to the skeletal organs and 

 especially the teeth, and the author loses no opportunity of 

 forcing home the lesson of the tooth-scale homology. The 

 effort, however, is somewhat weakened by the assertion 

 that, while fish-scales are (p. 29) typically" horny plates," 

 they are (p. 31) in ''the most primitive form" bony. 

 The statement that the bony fin supports (p. 68) have 

 been formed by the fusion of clusters of original " hair- 

 like ' rays is equally misleading ; and in dealing with the 

 terms expressive of types of tails, the author falls into 

 the prevailing fallacy of applying them to the fins and 

 not to the fishes themselves. In declaring that in the 

 typical fish the dorsal fins are two in number, the fact 

 that there may be three dorsals is ignored, it being im- 

 plied (p. 58) that the codfish has but two. And error is 

 further evident in the assertion that the adipose fin is 

 " without supportmg structures." 



The mode of description is in places none too well 



chosen. Such declarations as that the " beauty " of the 



Cestracion's teeth is "entirely an accidental feature" and 



that in deglutition the "touch "of the swallowed food 



NO. 1680, VOL. 65 J 



''signals" through the closed-up gullet to the nerves, are 

 to be deprecated in a book of this kind ; while a greater 

 regard for the facts of morphology would have been in 

 places acceptable, as in the mode of treatment of the 

 types of so-called external gills. The existence of these in 

 the Teleostei is denied ; but while we excuse the 

 non-allusion to those said to occur in the loaches, we 

 consider it strange that, on a later page, the author in- 

 cidentally refers to the African fishes obtained by 

 Budgett, in which they have been proved to be 

 abundantly present, without mentioning them. Nor is he 

 more fortunate with his treatment of the internal gills and 

 respiration, for nowhere in the book are the numerical 

 limitations of the former even stated, nor is there mention 

 of the "breathing valves," to which attention has but 

 recently been redrawn. 



In the aforenamed and other equally important 

 matters, which, under the scheme adopted, should have 

 found recognition in the book, the author is not up to date, 

 as, for example, in his declaration that nothing is known of 

 the chims-roid development. In the organologica! sections 

 of the book sufficient use is never made of extremes of 

 modification, such, for example, as those which render 

 clear the real differences in the composition of the gills 

 of the bony fishes and elasmobranchs, expressed in the 

 terms pectino- and cysto-branchias. Particularly is this 

 the case with the alleged distinctions between the two 

 chief groups into which the author would divide the 

 fishes as a whole. He gives, for this purpose, a classifica- 

 tion, which is neither that of the author to whom he 

 ascribes it nor an accurate statement of Huxley's ob- 

 servations, upon which it is based. "Hyostylic" and 

 "autostylic" are the terms which denote the distinctive 

 characters of his two great "branches," but the former 

 is wrongly construed. Neither the author of the present 

 work nor he whom he names acknowledge the condition 

 termed by Huxley the aniphistylic ; and the author him- 

 self does not even mention the Notidanidne, of which, 

 alone among livmg fishes, it is diagnostic. These and 

 the Port Jackson shark (which e.xhibits a marvellously 

 transitional condition of the parts in question, for which 

 alone a distinctive term might well be introduced) are 

 not typically hyostylic. They are lower than those fishes 

 which are. Without recognition of them and the amphi- 

 stylic state Huxley's system cannot be adequately set 

 forth. So important is this morphologically that advan- 

 tage might be gained by associating the Notidanidae with 

 at least the Hydodonts and Pleuracanths among fossil 

 forms, in a distinct order, in preference to the retention 

 of the name " Ichthyotomi " for the latter alone. In the 

 present case, in the non-recognition of these amphistylic 

 forms and the absence of all reference to the hyomandi- 

 bular element, the essential point is lost. In the spread 

 of scientific knowledge, the more elementary that imparted 

 the more precise should be the diagnoses employed. 



There is a closing chapter on pal.eichthyology, of a 

 very cursory type. 



The present book is the second which the author has 

 contributed to the series to which it belongs. The first, 

 on " The Story of Bird Life," was in every way a success 

 and as a popular treatise exemplary. Comparison shows 

 that the striking differences between the two books are 

 due to the fact that with the first of them alone the 



