March i6, 191 i] 



NATURE 



n 



In speaking, on p. 58, of the "black and white" 

 varieties of Pseudacraea lucretia approaching- the 

 Danaine model Amauris echeria, the author is evi- 

 dently referring to the individuals in which the normal 

 white markings are to a greater or less extent replaced 

 by ochreous. 



It would have been appropriate to place Acraea 

 esebria among the mimics of Planema aganice and 

 its form montana (pp. 73-5). Furthermore, aganice 

 is not "confined to the Natal region," but occurs in 

 south-east Rhodesia and probably much farther north 

 along the east coast. A. esebria, too, is not only 

 southern (p. 81), but eastern in distribution. 



Entebbe is given as the only locality of Pseudacraea 

 hobleyi on p. 78, but its female, originally described 

 as tirikensis, was first collected by Mr. C. A. Wiggins 

 in a more eastern part of the circumference of the 

 Victoria Nyanza, viz., Tiriki and Nyangori. It has 

 been also received from Toro. 



The Pterothysanid moth Hibrildes neavei is not 

 "bisexually mimetic, and corresponds to the two 

 sexes of Acraea anemosa " (p. 103). The mimetic 

 Hibrildes is only known as a female, which probably 

 belongs to one of the previously known non-mimetic 

 males. 



The admirable account of the most wonderful mimic 

 in the world, Papilio dardanus, is accompanied by 

 plate X, entirely devoted to the forms of this species 

 and the allied P. tneriones of Madagascar. The part 

 of the preliminary list on p. 92 would have been better, 

 [from the point of view of evolution, as well as that of 

 geographical distribution, in the order polytrophus, 

 dardanus, tibullus, cenea. A more serious error in the 

 same part of the list is the inclusion of the female forms 

 dorippoides and trimeni in the sub-species cenea, in- 

 stead of tibullus, although both are correctly placed 

 in the full account on p. 100. The male of dardanus 

 lis inadvertently described as black and white on 

 'ap. 93-4, although its "pale yellow ground-colour" 

 ^is correctly spoken of on p. 97. The males of tibullus 

 jl Elast Africa) are characterised by the strong develop- 

 nent of the black submarginal band in the hind wing, 

 rhose of cenea (South Africa) differ in the smaller 

 ievelopment of this feature. It increases rapidly as 

 ve pass northward, the cenea males being transi- 

 ional into those of tibullus. The account on p. 100 

 onveys a nearly opposite impression. 

 The classification of so complex a subject as mimicry, 

 inder the limitations imposed by the ordinary printed 

 )age, must always be a matter of great difficulty. In 

 iome respects the author has not grappled with it 

 'ery successfully. Thus his admirable account of the 

 nimics of Danaida chrysippus does not seem to be 

 ery happily arranged. The species follow the order 

 •f the following column, the members of no single 

 amily or sub-family being all together : — 



1. Hypolimnas misippus : Nymphalinse. 



2. Pseudacraea poggei : , , 



5. Acraea encedon : Acrseinae. 



8. Mimacraea marshalli : Lycrenidze. 

 4. Argynnis hyperhius : Nymphalinae. 

 7. Acraea mima : Acrseinse. 



6. Acraea wigginsi : „ 



9. Cooksonia trimeni : Lycrenidae. 



3. Diestogyna iris : Nymphalinse. 



NO. 2159, VOL, 86] 



In spite of this dislocation of the groups in the text, 

 we find that all four Nymphalinae are near together 

 on plate ii, while the three Acraeinae and the two 

 Lycaenidae are also together on plate iii. The most 

 obvious sequence on the plates is that indicated by 

 the numbers to the left of the column, a sequence far 

 better than that adopted in the text. It is, in fact, 

 the best possible arrangement, except for the position 

 of Argynnis hyperbius, which, being restricted in 

 Africa to Abyssinia, is best placed at the head of the 

 list — as far as possible from all the rest. It would 

 then be followed by the wide-ranging H. misippus, 

 the only Nymphaline mimic with which it is asso- 

 ciated. The remaining seven species, together with 

 H. misippus, form a very natural group, some of 

 them wide-ranging, the others, except the more equa- 

 torial A. wigginsi, especially characteristic of northern 

 Rhodesia. 



Having in view the needs of naturalists who are 

 beginning the study of mimicry in butterflies, and 

 we hope that large numbers of them will seek the 

 valuable and important help offered in this beautiful 

 work, it would have been advantageous to make the 

 group-names a prominent feature in the descriptions 

 of the plates, and also to print comprehensive descrip- 

 tive titles beneath the plates themselves and above 

 the descriptions of each. Thus plate ii. might have 

 been briefly explained as " Danaida chrysippus and its 

 Nymphaline Mimics." The arrangement of models 

 and mimics in separate columns in the description of 

 the plates is an admirable feature, as also is the print- 

 ing of the names of the species beneath the figures 

 on the plates themselves. 



The succession of the models in the text might also, 

 we think, be improved. Thus the deeply interesting 

 series of Planemas with Pseudacraea mimics, begun 

 on p. 65, is interrupted (pp. 66-9) by the great black- 

 and-red combination ranged round Acraea egina, and 

 by the purely Nymphaline association of Crenis and 

 Crenidomimas (p. 70), and then again resumed on 

 pp. 70, 71, et seq. 



The author has wisely preceded his account of 

 mimicry by a classification, on pp. 11, 12, of the chief 

 butterfly groups, with a few of the main features by 

 which each is distinguished. Such a classification 

 will be of great value to those who are beginning the 

 study of mimicry in the field, and have not the means 

 of referring to the literature of the subject. It is a 

 pity, however, that the Brassolinae and Morphinae are 

 separated from their close allies, the Satyrinae, by the 

 intercalation of the Acrasinae and Heliconinae— these 

 latter being themselves similarly cut off from the 

 Nymphalinae, to which they bear so close an affinity. 

 The author is here following in the main the key 

 given by Mr. Roland Trimen in his South African 

 Butterflies ; but in this great work a linear arrangement 

 based on affinity is printed on the opposite page, and 

 is adopted throughout the volumes. 



It is also unfortunate that the division of the 

 " Heliconidae " of Bates into Ithomiinae and Heli- 

 coninee is recognised neither in the classification nor 

 in Mr. Eltringham's further discussion of the groups 

 on pp. 17, 18. The composite nature of the " Heli- 



