58o 



NA TURE 



{Oct. 2 1, 1880 



however very possibly exist e\'en though quite imper- 

 ceptible to us. Most of these organs occur in male 

 insects only, whereas it is undoubtedly the case that the 

 males discover the females at great distances, and we 

 should therefore anticipate that the latter would have the 

 scent-producing organs, the former the sense-organ 

 capable of perceiving the odour. The investigation of 

 this obscure subject is however still in its infanc)-. 



Whether the antenna: are organs of touch only or of 

 some other sense is yet undecided, but the question might 

 probably be solved by an experimenter as ingenious and 

 persevering as Sir John Lubbock. Mr. Svvinton speaks 

 of the male butterfly or moth " running over his partner 

 with snuffing antennee," but this is begging the question ; 

 and the following observation, though interesting, does 

 not throw much additional light on the subject : " One 

 dull afternoon on the 4th of September during the wet 

 season of 1879 my eye was arrested by the pretty dappled 

 wings of a female of the large Magpie Moth who was 

 flying most purposely from leaf to leaf along a hedgerow. 

 She successively visited a reddening bramble, a hawthorn, 

 clematis, and guelder-rose, fruitlessly touching over their 

 glandular surfaces with a quick alternate vibration of her 

 black antenna;, in search, as I at first supposed, of honey- 

 dew. The crisping foliage of a thorny sloe finally arrested 

 her, and seemed to confer satisfaction on her tactile per- 

 ception ; for raising simultaneously her feelers and crawl- 

 ing on to the centre of a leaf, she hung on at its upper 

 surface, elevated her wings, and by curling her abdomen 

 round its apex, began to methodically attach her oval and 

 shagreened eggs to the underside close to the midrib. 

 She could distinguish Souchong from Pekoe." 



The account of light-giving insects is very unsatis- 

 factory, the old theory of the light serving as a guide and 

 attraction to the male being the only one given. Yet in 

 the list of luminous insects appended to the chapter we 

 find no less than six cases recorded in which larva: or 

 pupEe are luminous, a fact which might surely have 

 suggested a doubt as to the use of luminosity as a sexual 

 attraction in the case of the glowworm and fireflies. 

 There being so many luminous larva:, taken in connection 

 with the fact (not mentioned by Mr. Swinton) that glow- 

 worms are distasteful to birds, renders it almost cerlain 

 that Mr. Belt's explanation is the true one, and that 

 luminosity is, primarily, a warning of uneatableness, and 

 is therefore a protective character, though it may of 

 course, like colours, serve the purpose of aiding discovery 

 and recognition by the opposite sex. 



The whole subject of colour is treated with vagueness 

 and indecision, and we find no systematic grouping of the 

 facts nor any firm grasp of a principle by which to 

 interpret them. The following characteristic passage will 

 illustrate these deficiencies :—" The attractive quality of 

 insects' colours from the foregoing appears nearly that 

 presented to the human eye, and, utilised in sedentary or 

 aerial display, originates phenomena of love and rivalry, 

 battles, dances, and gregariousness in evident parallelism 

 with those evoked by music. But this attractive virtue, 

 which must be considered as stimulative, does not reside 

 especially in either sex, as some at first sight might be 

 inclined to assert ; for wc find conspicuous colorisation, 

 though for the most part distinguishing the males, some- 

 times by a species of inversion appearing in the females ; 



the sexes also are often very similar in hue. And the 

 reason of this is that the females very generally attract 

 the eager males by sedentary display, of which the moth 

 kind affords notable instance. Here we may remark the 

 paler hues of many heavy Bombycina females who exhibit 

 on herbage, and the grey, white, or satiny shades of 

 moths that repose on tree-trunks, sexually marked in the 

 Gipsy Moth, who is rendered in measure terrestrial by 

 her limp wings. Others more or less apterous, like the 

 Vapourers and Psychidas, owe what little chromatic 

 attraction they possess to their conspicuous cocoons." 



There is hardly a sentence in this paragraph that is not 

 open to discussion or that is not more or less inconsistent 

 with some other sentence ; while the whole is completely 

 neutralised by the succeeding paragraph which goes on 

 to describe how the male moths are evidently attracted to 

 their partners by odour, and not by sight at all ! 



The chapter on the sounds produced by insects is 

 crowded with interesting observations and is certainly of 

 great value, yet here too we meet with the same looseness 

 of remark and incapacity to see the importance of certain 

 facts. Thus, we find the strange, and in the present 

 state of our knowledge altogether unproved statement, 

 that — '■' In Lepidoptera music is in direct relation to 

 colour, sound to beauty ; " while the fact that the pupal 

 form of some Hemiptera stridulate, taken in connection 

 with many proofs that the sound is produced under the 

 influence oi fear, shows that in some cases at all events 

 these sounds are protective rather than sexual ; and this 

 opens up a field of inquiry analogous to that of the 

 diverse uses of colour, but which our author passes over 

 almost without remark. 



Among the smaller errors and misconceptions in the 

 volume we must note the statement that Darwin adopts 

 the pressure theory of the formation of the bee's cell 

 (p. 58) ; the total misconception of the theory of mimicry 

 (at p. 81); and the extraordinary account of tropical 

 colour, certainly evolved out of the writers own conscious- 

 ness. He says : — " In the Brazils, for example, all colours, 

 whether of Ijirds, insects, or flowers, are brilliant in the 

 extreme. Blue, violet, orange, scarlet, and yellow are 

 found in the richest profusion, and no pale faint tints are 

 to be seen" ! In the matters of Pateontology and glacial 

 epochs the author's authority is Mr. Page ; but the subject 

 is evidently beyond him, for he confounds the precession 

 of the equinoxes with the obliquity of the ecliptic, and 

 winds up with "glacial phenomena at the poles now 

 exposed to the continuous action of cold interstellar 

 space, with a collapsing in the earth's superficies, giving 

 birth to the ensuing wrinkling marked by earthquakes, 

 volcanic action, and land depression, or vice -c'ersd." 



We also notice many errata, indicating some carelessness 

 in passing the volume through the press. Dr. Falconer 

 is called "Faulkener" (p. 15) ; anthropods is written for 

 arthropods (p. 86) ; Leucanida: for Lucanidas (p. 99) ; 

 Grophilus for Geophilus (p. loi) ; and Libuella for 

 Libellula (p. 311) ; but the chief fault of the volume is a 

 constant effort at fine writing, which, combined with an 

 inveterate obscurity of style, often renders it utterly im- 

 possible to comprehend what is meant. Scores of passages 

 might be quoted illustrative of this peculiarity, but the 

 following will serve our purpose : — 



" Dealing with geological chronology, the phenomena 



