November 4, 1897 J 



NATURE 



All this is the most utter folly; the struggle for exist- 

 ence is now what it has ever been, fluctuating in degree, 

 but always severe, and we know that when a species is 

 shielded from the struggle as regards any part of its 

 organisation, that part is very far from maintaining an 

 equilibrium unchanged. 



The suggestion that the unpalatable qualities are due 

 to the juices of the food-plant of the larva has often been 

 made before, but never with so much insistence as in 

 Haase's work. He quotes a number of cases in support 

 of his contention, and neglects those which oppose it. 

 Haase would apparently deny to insect physiology the 

 power to construct a protective odour or flavour, although 

 the laboratory of an insect's body has been shown to be a 

 marvellous workshop producing all kinds of unexpected 

 compounds, and although the food-plants of many of the 

 commoner of our distasteful European moths do not 

 belong to any poisonous or acrid category. Although it 

 is possible that the noxious or nauseous qualities may, in 

 certain instances, be borrowed ready-made from plants, 

 such an origin is as yet unproved ; while its universality, 

 as assumed by Haase, has been effectually disproved. 



For a work of such great pretensions the want of a 

 wide and adequate acquaintance with other writers is 

 somewhat remarkable. Thus Dixey's memoir on the 

 Phylogeny of the wing-markings of Vanessidas and 

 Argynnida;, as well as that on the Pierinae should have been 

 consulted ; for the author often attempts to reason upon 

 the same lines, without having devoted any special study 

 to the subject. In speaking of the different forms of the 

 female of Papilio merope {cenea) he states (pp. 45, 46) that 

 Mansell Weale captured -a. large number. In reality, the 

 evidence supplied in support of Trimen's argument that 

 these different forms were the females of a single species 

 with a very different male, was of a far more satisfactory 

 kind ; for Mansell Weale bred all the forms as well as 

 the male from larvas taken upon a single tree. Further- 

 more, no account of this most remarkable case can be 

 regarded as adequate without a detailed reference to 

 Trimen's classical paper. The reference is here and on 

 p. 104 of the most meagre and unsatisfactory kind. 

 Again, there is no allusion to Westwood in the account 

 of the early history of the subject, or to Gahan in the 

 account of mimicry in Coleoptera (p. 131). In his con- 

 sideration of the classification of mimicry, warning 

 colours, &c., suggested by the present writer, the author 

 is satisfied with the study of a second-hand account of an 

 easily accessible work. 



Again, on p. 123, Haase states that Wallace, as well as 

 Fritz Miiller, originated the explanation of resemblance 

 between inedible species and genera. As a matter of 

 fact, we owe to Fritz Miiller alone the important sugges- 

 tion that forms which resemble each other and thus com- 

 bine their advertisements, so to speak, are recognised 

 with a smaller expenditure of lives than those which 

 possess independent advertisements, each of which re- 

 quires to be learnt separately. The fact of such resem- 

 blance was first recognised by Bates, but its explanation 

 remained a difficulty under the theory of mimicry which 

 we received from him. Wallace freely acknowledged the 

 debt which we owe to Fritz Miiller, and at once saw the 

 great and far-reaching importance of the new suggestion. 

 One great fault of the present work is the failure to 

 NO. T462, VOL. 57] 



recognise this importance, and the attempt to explain 

 nearly all cases on the lines of Bates' theory of specially 

 protected model and defenceless mimic, instead of con- 

 stantly introducing the useful conception of resemblance 

 for mutual advantage between specially protected species 

 and groups. 



Thus, to take but a single example, the treatment of 

 the resemblances of the Erycinidae (pp. 61, 62), as well 

 as that of some of the Pierine genera, would have 

 received much light from the Miillerian standpoint. 



On p. 134 the distinction between protective and 

 aggressive mimicry is ascribed to the present writer, 

 although it was made by many writers long before he 

 contributed anything to the subject. Having made this 

 error, Haase goes on to criticise the cases included under 

 the latter term, stating that "the disguise itself always 

 serves only as a means of protection, and never as a 

 weapon of attack, even when borne by the aggressors." 

 He then proceeds to destroy his own criticism by citing 

 several cases (p. 135) in which he maintains that the 

 resemblance does act as a weapon of attack. It is 

 to be hoped that the translator is to some extent re- 

 sponsible for this .tissue of mistake and self-contradiction. 

 At the moment of writing, access to the German original 

 is impossible. 



There are a number of errors in the systematic part of 

 the work which we should hardly expect to see. Thus 

 the name Hypoliinnas boliiia (L.) is given when H. 

 misippus (L.) is intended (p. 41), and the appearance of 

 the type form is wrongly ascribed to the var. inaria{CY.), 

 although this may be a mistake of the translator. In 

 Plate xi. (Fig. 76) an Anthoinyza is described as a 

 Hyelosia, and in the same plate an undoubted representa- 

 tion oi Methona confusa (Butl.) in Fig. 78, is stated to be 

 Thyridia psidii of Linnaeus, the author being careful to 

 add the words " not Methona " after the generic name. 

 There has been much confusion between these two 

 closely convergent, although in reality widely diffierent 

 species — so much so indeed that even Bates was deceived 

 — but the account given by Godman and Salvin in the 

 " Biologia " places the matter on a secure basis, and 

 clearly shows that the Linnean species is Thyridia psidii^ 

 possessing white spots on the black border of the hind 

 wing. The latter species is also distinguished by a small 

 reddish spot at the base of the fore wing ; and both these 

 characteristics being absent from Fig. 78, we can only 

 conclude that it represents the species of Methona from 

 which they are also absent. A very unaccountable error 

 is the positive statement (p. 145, note) that there are no 

 " unmistakably mimetic species " among the Lepidoptera 

 of Madagascar. The author must surely have been 

 aware of the occurrence of Hypolimnas misippus (L.) in 

 that island. In the same note the impression is conveyed 

 that there is a widespread belief that isolation, as in 

 islands, rather than the keener competition of continental 

 areas, favours mimetic modification ; and Haase ap- 

 parently takes some credit to himself in supporting the 

 opposite view. But the ancestral character of island 

 faunas in relation to mimicry was recognised long before 

 the appearance of Haase's work, and has never been 

 seriously disputed. 



Another obvious error occurs on pp. 147, 148, where 

 the resemblance of the iinagos and not the lan'(Z, as 



