178 



HARDWICKE'S SCIENCE-GOSSIP, 



sufficiently decided to recommend this matter to the 

 trade, but speaking for myself I may state, that when 

 extraneous matter had been eliminated from the 

 records of two years' trial, I could fairly attribute to 

 this source variations in size, and in cases a decided 

 abstraction of the ordinary colouring principle, so as 

 to confer what the Germans designate a clear look to 

 the wing. Thus tiger-moth caterpillars, when sup- 

 plied with lettuce leaves, I found fed up rapidly and 

 produced large moths ; while those fed on herb 

 Robert {Gera^iiiun rohertianiim), an uncongenial 

 food, produced small and colourless ones. 



The proper manner to proceed on the analysis of 

 the constitution of the organic frame, is doubtless, if 

 possible, to obtain the ova of a butterfly or moth 

 and to rear them from this stage on a food plant 

 affected by another individual of the same genus, or 

 otherwise ; but as this will be often impracticable, 

 the caterpillar itself may be obtained and tried with an 

 unusual food ; and even if it does not readily take to 

 it, there is no need of despairing, as the transference 

 may be at times accomplished by mixing the new diet 

 with the usual nourishment. For example, I found the 

 caterpillars of the small tortoiseshell were not natur- 

 ally partial to hop leaves, but by means of a judicious 

 mixture of hop and nettle, I finally induced them to 

 quit their proper food and partake of the amber juice 

 of intoxication, and a certain percentage of clear 

 coloured individuals resulted. One of these is shown 

 (i) fig. 88, in the former portion of this paper, where 

 for "willow" read "hop." On proceeding, how- 

 ever, to surmise that a little rouge might be detected 

 mingling in the sallow complexion of these fallen ones, 

 one of my coiTCspondents took exception ; and of 

 course, as regards change of colour, some may go 

 yet further, and fancying this might be negatived by 

 some physiological conception of a unity of organic 

 principle in the circulating fluid, raise a question 

 forthwith how change in food can affect the capabilities 

 of the secreting glands : I do not think nevertheless 

 that certain medicinal practice, inoculation for in- 

 stance, at all favours this idea of homogeneity ; and if 

 we descend from the regions of theory to those of fact, 

 we have it emphatically recorded that Mr. Gregson 

 obtained a percentage of black tiger-moths from a diet 

 of coltsfoot, and more recently we find the same 

 authority recommending beetroot as a cosmetic 

 ("Zoologist," 1861). Mr. Gregson found /5'^. ^wa-- 

 phala fed on sycamore, fine and dark ; Xylo. poiyodoii, 

 fed upon heather, always dark ; Hadeiia adusta, do. ; 

 Acrony. Menyanthidis, fed on willow, on the contrary^ 

 produces the variety of Curtis Salicis, fed on heath it 

 is light. Cidariapopulata, fed on Vaccinium Myrtilbis, 

 is light, on V. Vitis-Idcva darker ; ////'. defoliaria, fed 

 on birch, better marked than when reared from elm. 

 Ejip. venosata, fed on inflated catchfly, is almost white, 

 on shore catchfly, larger and almost lead colour ; 

 Noctiia f estiva fed upon thorn, rich red ; on grasses, 

 light yellowish ; N. triatigiiliiin, fed on thorn, dark 



and rich ; Ab. Grossulariata, fed upon currant, produce 

 a light brood ; on wild plum, a dark or yellowish 

 one. 



The potency of food to produce change is not 

 confined to the wings of the butterfly, we are led to 

 surmise, but exerts its influence from the larval stage. 

 Thus for example, at page 279 of the sixth volume 

 of the "Entomologist's Monthly Magazine," Mr, 

 Buckler records the discovery of two forms of cater- 

 pillar producing the painted-lady butterfly in England ; 

 the one densely covered with pale grey hairs found 

 on mallow {Malva sylvestris), and the other "clothed 

 with spines alone " feeding on thistle: so that here 

 then as in the case of the small tortoiseshell already 

 noticed we have the following interesting problem 

 presented us. Determine the distribution of the 

 spiny and hairy sorts, and examine their relations to 

 their progeny. But to return. When species are 

 dwarfed, certain erratic elements arise in the patterns 

 of the wings. As is known from a passing notice in 

 Coleman's Httle book of butterflies, dwarf examples 

 of the large tortoiseshell may be obtained by 

 feeding their caterpillars on willow, an unnatural 

 food. Some years back I had a number of these in 

 London, and no food near at hand, save the leaves 

 of a very grimy willow that overhung the road from 

 a neighbouring garden. The result was I bred not 

 a few cripples and a goodly series of dwarfs ; one of 

 the more striking aberrations having among other 

 singularities an extra spot on either of the front 

 wings, appertaining evidently to the third of the 

 bands. See (4) fig. 88, in the former portion of 

 this paper. 



Starving likewise has a similar effect to an un- 

 natural food. It was about the same time, in the 

 spring or autumn of the year 1876, I think, that I 

 met with the late Mr. Ramsey Cox "who caught 

 Newman all those pale clouded yellow butterflies 

 at Margate ;" and we had a pleasant chat together 

 while the train proceeded from Brockenhurst station 

 to Waterloo. He had been entomologising in the New 

 Forest, and I remember among other items of informa- 

 tion he mentioned that he had recently obtained some 

 curious dwarfs of the species of Vanessa by simply 

 starving the caterpillars. One peacock, as he else- 

 where describes, had no ocellus to the hind wings, 

 one small tortoise-shell possessed a brownish patch 

 (indicating the central band), and another had black 

 wing veins. Mr. J. B. Hodgkinson, some ten years 

 earlier, relates a similar experience, and speaks of 

 examples of the tortoiseshell obtained from cater- 

 pillars "that had been let starve or eat the band- 

 box ; " as having black nervures, wanting the discal 

 spots, or being of a buff variety. ("Ent. Mon. Mag." 

 1867. "Entomologist," vol. 1876, pp. 58, 252.) 

 Such facts may eventually point out that some of 

 the seasonal or climatic races of butterflies found 

 on mountain slopes and in northern regions, and 

 intrinsically due to retardation of metamorphosis^ 



