April 2, 1896] 



NATURE 



507 



the diseases of larva; and pupic are dealt with at greater 

 length than is often the case in similar manuals. With 

 regard to the section on the care of a collection, our own 

 opinion would be in favour of considerably amplifying 

 the suggestions here thrown out as to labelling and 

 register-keeping. 



It is, however, to the experimental and speculative part 

 of the work that the scientific reader will turn with most 

 interest. Here he will find a large mass of valuable 

 material ; consisting in the chief place of elaborate 

 records of the author's own experiments. The first 

 subjects dealt with are those of hybridisation, the 

 respective influence of the male and female parent on 

 the structure and appearance of the hybrid progeny, the 

 fertility of crosses, the production or suppression of inter- 

 mediate forms. The value of well-planned and systematic 

 experiments on these points cannot be easily over- 

 estimated. The importance of the subject has been fully 

 recognised by Darwin, Wallace, Galton and Weismann 

 amongst others, but the comparative absence of quantita- 

 tive results such as Dr. Standfuss gives us, and the 

 consequent impossibility of applying any measurement to 

 the forces at work, has hitherto prevented the facts of 

 hybridisation, their relation to fertility, and their bearing 

 on questions of heredity and species-formation, from 

 having their due weight in the discussion of biological 

 problems. Another large and most interesting group of 

 experiments centres round the question of the effect of 

 abnormal external conditions, duringthe immature stages, 

 upon the form of the perfect insect. The author has 

 here taken as his model the well-known temperature 

 experiments of Dorfmeister, Weismann and W. H. 

 Edwards upon lepidopterous pupie, elaborating the con- 

 ditions and extending his investigations over a wider 

 range of material. It is remarkable that the species 

 selected by him as the subjects of experiment were in 

 very many cases the same as those used by Merrifield, 

 who had already been working quite independently on 

 similar lines, and most of whose results, published before 

 those of our author saw the light, are in close agreement 

 with the latter. The work of each experimenter thus 

 receives independent confirmation from that of the other 



While there can be no question of the remarkable 

 interest attachmg to the effects obtained by these 

 temperature-experiments upon pupae, and while it w^ill be 

 generally allowed that much gratitude is due to Dr. 

 Standfuss for his assiduity in conducting and recording 

 the large number of experiments here referred to, and in 

 accurately describing their results, there will be much 

 difference of opinion as to the value of his interpretations. 

 Dr. Standfuss's own views on the subject of evolution 

 may be shortly stated. He believes in the hereditary 

 transmissibility of acquired characters ; and without enun- 

 ciating any definite theory of the nature of pangenesis, 

 he argues in favour of a centripetal mode of germ- 

 formation. V'ariations are, according to him, produced 

 by the direct effect of the environment on the parent 

 organism, and the principle of natural selection is limited 

 in operation, many species having become established 

 \v ithout its aid. The theory of mimicry, he thinks, has 



! tainly to be reckoned with, but great caution must be 

 cl in applying it to the explanation of any given case. 

 NO. 1379, VOL. 53] 



Of Fritz M tiller's development of the mimicry theory, in 

 consideration of which many of his objections would 

 lose their force, he takes no notice. From all this it may 

 be seen that our author is a pronounced Neo-Lamarckian 

 Space would not allow us to follow him in all his specu- 

 lative arguments, which, though often far-fetched and 

 sometimes demonstrably erroneous, are always ingenious 

 and interesting. Recognising the extreme value of facts 

 in reference to such a question as that of the true nature 

 of heredity, we have carefully searched the whole volume 

 for any unequivocal instance of the genuine transmission 

 of an acquired character, and we are bound to say that 

 we have not found one, unless in the sense admitted by 

 Weismann ("The (ierm-Plasm," 1893, p. 401), which, 

 strictly speaking, is not a matter of heredity at all. The 

 author has evidently convinced himself that several of 

 his results are to be interpreted in the former, viz. the 

 Lamarckian way. For our own part, we can only say that 

 they seem to us to be all capable of other explanations ; 

 and that in spite of the difficulty he alleges (p. 292), the 

 only means of attempting a satisfactory solution of this 

 question, as it appears to us, would be a careful experi- 

 mental inquiry pursued through several generations. For 

 this purpose some species should be sought for which is at 

 the same time capable of partial domestication, and pos- 

 sesses distinctive features of colour and pattern which are 

 fairlysensitive to external influences. An argument against 

 Dr. Standfuss's view of species-formation is afforded by 

 the curious reversionary character of many of the changes 

 produced by exposure of the pupa to abnormal conditions 

 of temperature. The ancestral features thus revived are 

 sometimes of so very distinct and special a kind, that it 

 seems scarcely adequate to regard them, as he does, 

 simply as the direct effect of temperature conditions 

 similar to those under which the ancestral form came 

 into existence. But our author practically ignores the 

 possible influence of sexual selection and of the necessity 

 for recognition in the production of characteristic external 

 markings, and with him "adaptation " as applied to these 

 markings means little else than protective resemblance. 

 Hence, probably, his limited view of the action of natural 

 selection, and his readiness to attribute the distinct 

 aspects of the various species of Vanessa and other 

 groups to direct climatic influences, ^/«^- isolation. Still, 

 whatever may be the omissions and shortcomings of the 

 book from the theoretical point of view, of which much 

 more could be said, its value as a great quarry of facts 

 is undeniable, and the author makes no attempt to 

 present his experimental results in any but the most fair 

 and impartial manner. 



The value of the descriptions is greatly increased by 

 the excellent plates, which are very well executed and 

 really illustrative of the text. The book is well printed ; 

 we have only discovered a very few misprints in the text, 

 and one small inaccuracy in one of the plates. The want 

 of a general index is a serious drawback. Taking the 

 work as a whole, we are bound to say that it is one that 

 challenges the serious attention of biologists, and that 

 whatever may be thought of the author's speculations 

 and arguments, the facts that he has collected are of 

 unquestionable interest and importance. 



F. A. DiXEV. 



