54 BRITISH BUTTERFLIES. 



growth of the seedpod, or similar frequently-met natural peculiarity, 

 whilst that of E. euphenoides bears a similar resemblance to one or 

 other of the peculiar structures of Biscutella laevigata. It appears to 

 be a fixed habit in Euchlo'e, however, as already noticed, to produce no 

 "forwards," i.e., the species preserve a purely single-brooded habit, e.g., 

 although both E. euphenoides and E. cardamines are in the imaginal 

 state in April in southern Europe, and f ullfed larvae may often be obtained 

 before the end of the month ; there is no record of any attempt at 

 forming a partial second-brood in either of the species ; similarly, 

 Scudder says that E. genutia is quite single-brooded, and, like the 

 two European species already noted, the larval life lasts only from two 

 to three weeks. This is the more remarkable, because all the allied 

 genera, Anthocaris, Pontia, Pieris, etc., have, as we have already 

 shown, larvaB noted for their frequent development of a" forward " 

 habit. Like the rest of the Pierids, however, the species of Euchlo'e 

 have purely summer-feeding larvae. 



It is to be observed that the essential food-habit of the larvae of Pierids 

 and Anthocarids is the selection of cruciferous plants. Not that they 

 are confined to such, e.g., Pieris rapae may go out of its way to choose 

 Tropaeolum, and Pontia daplidice to choose Reseda, of various species. 

 Leptidia sinapis, with real Anthocarid larval habits, i.e., purely-summer- 

 feeding, developing "forwards " in warm summers (and a consequent 

 partial second-brood), fails to adopt the cruciferous food-habit, and 

 selects Lathyras and Vicia, in this respect following the food-habit of 

 the allied Coliad larvae, and, not only is this so, but it follows the 

 resting-habit adopted by the Anthocarids, for, being long and slender, 

 it rests stretched out along a stem or petiole of a leaf, with which its 

 colours assimilate exactly, the white stripe on the larva representing 

 light and shade effects on the plant, whilst, in the youngest larvae, the 

 hairs also aid in its resemblance to the general aspect of the plant. 

 The genus, therefore, as illustrated by our species, L. sinapis, has, 

 in its usual larval habits, although not in its food-habit, quite 

 Pierid leanings. It is a slender larva, obtaining protection by 

 its lethargy during the day, combined with its colour and striping, 

 produces "forwards" with facility under suitable meteorological 

 conditions, has wholly summer-feeding larvae, but, in its food- 

 habit, leaves the Pierids, which are so closely confined to cruci- 

 ferous plants, and follows the Coliads, by choosing leguminous 

 plants for food. Chapman observes that the colour and arrange- 

 ment of lines on the larva protect it excellently on Lathyrus 

 pratensis. The larva, for a Pierid, is rather long and slender, 

 and, stretched out along a stem, or a petiole of a leaf, is ex- 

 tremely difficult to see, the coloration being identical, the white 

 stripe of the larva representing light and shade effects on the plants. 

 In the youngest larvae the hairs agree very closely in general aspect 

 with those of the plant, greatly increasing the difficulty of observing it. 



