4 BRITISH BUTTERFLIES. 



the former among the EupJiorbiaceae, the latter among the Acalyphaceae, 

 Bentham and Hooker, on the contrary, place them close together in the 

 Plukenetieae, so that their close affinity which had been duly appreciated 

 by butterflies has finally been recognised by botanists also." 



Another remarkable fact connected with this subject is the narrow 

 range of plants from which some species have to select and the 

 wide range of others. Aglah urticae is confined to stinging-nettle, 

 Limenitis sibylla to honeysuckle, yet Polyyonia c-albuni has foodplants 

 as widely different as stinging-nettle, black-currant and hop, and 

 Pyrameis cardni as stinging-nettle, thistle, mallow and bugloss. 

 Still, on the whole, our butterflies have a very small range of foodplants 

 compared with that of many moths, some of which appear to be more 

 or less polyphagous, e.g., Saturnia pavonia (Brit. Lep., iii., p. 333), 

 Manduca atropos (op. cit., iv., pp. 432-3). In America, however, 

 Scudder notes that the "swallow-tail," Jawniades glaucus, feeds 

 upon plants belonging to no few r er than 15 different families. Not 

 only is the range of plants which a species chooses as food for its 

 larvae very restricted, but there is usually a very close alliance between 

 the plants selected by the 5 s of all the species of the same family, 

 e.g., all the European Urbicolid skippers choose grasses and rushes 

 of various kinds, the Hesperiid skippers on the other hand have 

 a much wider range among Malvaceae, Rosaceae, Leguminoseae , etc. ; 

 the Chrysophanids prefer plants belonging to Polygonaceae, the 

 Lycaanids and Coliads choose Leguminoseae, the Argynnids use Violaceae, 

 the Pierids Cruciferae, the Coenonymphids, Satyrids and Erebiids, 

 grasses, and so on. It will be known to most lepidopterists that these 

 general statements are largely true of butterflies belonging to these 

 groups throughout the whole of the Palaearctic and Nearctic regions. 



We have already noted that the egglaying habit of butterflies is 

 usually constant and fixed even to the extent of considerable detail. 

 Almost all butterflies lay their eggs definitely on their foodplant, the 

 only British species which appearsnot to do so being Melanargia galathca, 

 which drops its eggs loosely among the roots of the grasses on which 

 the larvae live. Occasionally a 2 of a species with a fairly constant 

 egglaying habit appears to blunder and will choose a dead stem of grass 

 or other object in the immediate neighbourhood of the foodplant, but 

 the occasions on which this happens are rare, and the choice of the 

 foodplant and the selection of an exact position in so many cases are 

 instinctive processes which have been brought to a high stage of 

 perfection in the development of the race. Chrysophanus virgaureae 

 chooses a dead or dying stem on which to lay its hybernating 

 egg. The choice of the foodplant, as we have already noted, is 

 almost certainly effected by means of scent. The antennal sensory 

 organs (among which those of scent are included) have been 

 worked out in detail (Ent. Record, viii., pp. 225, 261). We know that 

 the sense of vision is exceedingly limited in butterflies, and experiment 

 is against the assumption that they use their power of sight for 

 any such delicate discrimination as is required when they are selecting 

 a special species of foodplant on which to lay their eggs. On the other 

 hand, their movements, when on this important business, are such that 

 it would seem obvious that they are seeking by scent the plants on which 

 to lay. A ? will often settle on a dozen different plants similar and 

 dissimilar to that wanted before she finds the right one on which to 



