242 



NATURE 



[July 14, 1892 



passes current for scientific lecturing nowalays is mere 

 parrot -work ; and lecturing which is confined to mere 

 text-book recapitulation (such as could alone justify the 

 author's intention that his book should be used in the 

 lecture-room) is no lecturing at all, but rather a poor 

 form of dictation work. We deem it the highest aim of 

 a scientific lecturer to teach his hearers, by example, how 

 best to extend, systematize, and apply their knowledge of 

 crude facts previously acquired in the laboratory. He 

 should in all cases work out from these and lead up to 

 generalizations ; and, to the end in view, he should be up 

 to date in his reading, and, above all, cautious in his 

 selection of approved topics. Given this line of action, 

 the competent teacher could not fail to present his facts 

 in a manner in which they could not be found in any text- 

 book. The author of the work before us has clearly realized 

 this position, and much of his book which we presume 

 he would regard as the equivalent of lecture material, 

 fulfils our ideal. We note, however, a too frequent want 

 of judgment, and a too general desire to present theories 

 before facts. By way of example, the inter-relationships 

 of the Echinodermata are summarily dismissed in some 

 ten or a dozen lines, in a manner as "cocksure " as it is 

 certainly erroneous ; and the beginner is told (p. 377) that 

 the ribs of Vertebrates " perhaps bear the same relation 

 to the vertebrae that the visceral arches do to the skull," 

 before he either knows sufficiently what constitutes a rib, 

 or at all appreciates the difficulties in the way of homo- 

 logizing the ribs of the leading classes of Vertebrata. 

 And here and there the author goes out of his way to 

 raise difficulties at the outset {e.g. the opening sentence in 

 the book, and the second sentence of p. 121), when deal- 

 ing with terms having a definitely accepted meaning ; 

 while, in ushering in the Mollusca with a reference (p. 

 299) to " a diagrammatic summary of the chief anatomical 

 characters " and a "schematic Archi-mollusk — a recon- 

 struction of a possible ancestor," he proceeds along a 

 line subversive of all good discipline established either 

 on precedent or sound sense. There is here evidence of 

 a topsyturveydom in method, which could only be pro- 

 ductive of disastrous results. 



Concerning the more strictly text-book portion of 

 the volume, we confess to a similar attitude of mixed 

 judgment. There is in it much that is admirable and 

 beneficial, and not a little that is crooked and injurious. 

 The gastraea theory is swallowed outright, mention of 

 equally plausible alternative ones being confined (p. 62) 

 to five none too fortunate lines. The description of the 

 scapula (p. 472) as " a membrane bone," of the cranial 

 nerves of vertebrates (p. 381) as ten in number ; like the 

 assertions (p. 444) that " it is very difficult to distinguish 

 Amphibians from Fishes," that (p. 33) Volvox "is a 

 hollow sphere of epithelium," that the skate's egg-purse 

 is (p. 425) " composed of a horny substance allied to that 

 of hair and hoof" ; like definitions such as that of 

 Balanoglossus and Cephalodiscus (p. 348) as " surviving 

 incipient Vertebrates " (of course with a " notochord "), of 

 Lepidosiren (p. 428) as " only a species of Protoptsrus," 

 simply will not do ; while arrangements such as those of 

 the Mammalia (p. 7) and Vermes (p. 149) are hardly in 

 keeping with modern conceptions. 



Retrospective. — On retrospective examination of the 

 book before us, we seek in vain for evidence of that im- 

 NO. 1185, VOL. 46] 



press of the author's individuality as an actual worker 

 which has so often " made " the zoological text-book of the 

 past. The author has been too content to abstract all in 

 his way. Obsolete classifications are placed side by side 

 with others as audacious as they are premature, and 

 rival theories are alike abstracted for what they may be 

 worth. When, however, the author's method leads ta 

 the citing (p. 86) of Kropotkin as an authority on evolu- 

 tion ; to the placing side by side, as alternative interpre- 

 tations of the phenomena of Nature, those generalized 

 statements of facts which constitute the "laws" of 

 Darwin, and the flighty fantasies shot at a venture 

 by certain younger " law-makers " (some of whom are 

 sufficiently candid to admit that they are generaliz- 

 ing without facts), willing to risk all if, perchance, 

 a frivolous public will but proclaim them philosophers^ 

 the experienced naturalist, in whose hand the judgment 

 lies, steps in and demands a reconsideration. In a 

 word, the author has insufficiently exercised his judgment 

 in selection of material. To the teacher of science the 

 duty of showing his scholars, by inference, what to neglect 

 is, perhaps, of paramount importance to that of indicating 

 upon what they are to rely. The author of the volume 

 under review would, however, leave the discretion in the 

 hands of the student ; he writes rather as the amateur, 

 to whom everything is equally important, and in thus 

 acting he fails to recognize one of the highest functions 

 of his office, to the utter confusion, if not the ruin, of his 

 followers. In our opinion, his book, although in many 

 respects admirable, falls short in each of its great depart- 

 ments which we have signalized. It will be largely used, 

 and we wish it an ultimate success. It nevertheless con- 

 tains the framework of a really serviceable text-book ; 

 and if the author will elaborate this, using a fitting exercise 

 of judgment, and either eliminating the illustrations alto- 

 gether or replacing them in others better and more 

 numerous, he ought to produce a work of more than 

 passing value, and he would sufficiently justify the great 

 pains at which he has placed himself. In its present 

 form the book is calculated to encourage a love of 

 premature generalization, and anyone adopting its methods 

 would teach fantasies before facts. The mental attitude 

 which it typifies is one apt to create a bias, under which 

 the student would suffer in his after work, as is indeed 

 exemplified by the author himself in his treatment 

 (pp. 178-79) of the reproductive organs of the worm. 

 To encourage this is but to foster a growing evil. The 

 didactic method of instruction in zoology now in vogue 

 will unmistakably prevail in the future ; but, unless its 

 dryness be salted with work akin to the good old-fashioned 

 field work, to the discouragement of the more modern 

 and pedantic phylum-mongering and striving after im- 

 possibilities, better, by far, the regime of the past. 



G. B. H. 



WATTS' ''DICTIONARY OF CHEMISTRY." 

 Waits' Dictionary of Chemistry. Vol. III. By Forster 

 Morley and M. M. Pattison Muir, (London : Long- 

 mans, 1892.) 

 THE third of the four volumes of this excellent work 

 has just appeared, and in value and interest this 

 one does not stand behind the two previous volumes. 



