Jnt lateajTi Ji^>. 



A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. 



" To the solid ground 

 Of Nature trusts the mind which builds for aye." — Wordsworth. 



THURSDAY, NOVEMBER 4, 1897. 



MIMICRY IN BUTTERFLIES AND MOTHS. 

 Researches on Mimicry on the Basis of a Natural 

 Classification of the Papilionidce. Part ii. Researches 

 on Mimicry. By the late Dr. Erich Haase, Director of 

 the Royal Siamese Museum in Bangkok. Translated 

 by C. M. Child, Ph.D. Pp. 154 and 8 coloured plates. 

 (Stuttgart : Ernin Nagele. London : Bailli^re, Tindali, 

 and Co.\, 1896.) 



IT is, in some respects, a matter for regret that this 

 important and painstaking work has appeared. 

 The treatment falls far short of the pretensions of the 

 author, and is marred by numerous grave imperfections ; 

 and yet the plan is so comprehensive, and the amount of 

 valuable detail so great, that the appearance of a better 

 work will probably be long delayed. The detail which 

 forms the real merit of the work is piled together in a 

 most inartistic manner, so that every reader, except the 

 serious and determined student of the subject, cannot 

 fail to be repelled, and even to the latter the task will be 

 most tedious. And yet there is no subject which is 

 capable of being made more interesting and attractive 

 — alike to the beginner and the advanced student — than 

 mimicry. 



The volume deals with mimicry wherever it is found in 

 organic life, beginning with a brief mention of it among 

 flowering plants, and then giving a short account of its 

 occurrence in Arachnida, Orthoptera, Hemiptera, 

 Hymenoptera, Neuroptera, and Coleoptera. It is then 

 treated at great length and detail in the Lepidoptera, the 

 subject being divided on a geographical basis into the 

 models and mimetic forms of (i) the Indo- Australian 

 (2) the African, (3) the Nearctic, and (4) the Neotropical 

 regions. The mimicry of Coleoptera and Hymenoptera 

 by Lepidoptera is next briefly considered ; then follows 

 a short account of mimicry in Diptera, Mollusca, Ba- 

 trachia, and Reptilia (of the four above-named regions), 

 Birds and Mammals. The memoir concludes with an 

 important general section, dealing in various sub-sections 

 with the history and origin of mimicry in Lepidoptera, 

 NO. 1462, VOL. <^']'\ 



and the objections which have been raised against it, 

 and with the biological significance of mimicry in the 

 animal kingdom and its relation to other forms of 

 protective adaptation to the environment. 



The vast display of facts and details upon all points 

 prepares a reader to believe that the speculative part 

 of the work will be marked by extreme caution, and 

 guarded by the most scrupulous regard for all available 

 evidence. When, however, the author does begin to 

 speculate, he shakes off all restraint, and indeed in 

 most cases all prudence, and makes the rashest sugges- 

 tions as calmly as if they were well supported. Good 

 examples of this are to be found in most of his confident 

 statements as regards the past history of the warning 

 and mimetic groups in the Neotropical region (pp. 

 116-119); in the calm assertion that the variations 

 which have been developed into mimicry were due to 

 "an unfavourable condition of the species, which would 

 cause variations among the females"; in the conclusion, 

 for which the most inadequate evidence is offered, that 

 " the development of the Neotropince has reached and 

 passed its maximum" (p. 118). We do not often meet 

 with this combination of rash speculation with an almost 

 tedious collection and heaping together of facts, in 

 English works, perhaps because we are less patient in 

 the latter, rather than more cautious in the former. 



One very irritating feature of the work is the positive 

 statement of conclusions without any recognition or dis- 

 cussion of the obvious difficulties which they encounter. 

 Thus Haase's contention that what he calls the Melincea 

 type of colouring — 



" may be regarded as a characteristic expression of the 

 special, purely physical and chemical influences of the 

 Neotropic climate on a type of colouring originally black 

 and white" — 



is opposed by the want of evidence that effects so pro- 

 duced are hereditary — a difficulty which, at least, merits 

 consideration. Very similar, and even more annoying, 

 are the confident statements which are upset by other 

 statements in a different part of the work. Thus, on 

 p. 138 we are told in spaced type that "in all species 

 which are mimetic in both sexes the female resembles the 

 model more closely than does the male " ; while in other 



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