BUTTERFLY LARV.E AND THEIR MOULTINGS. 15 



They change colour very rapidly as the embryos mature, but the larvae 

 do not appear till late February or early March the following year. 



The eggs of Dry as paphia are laid in July and August ; the egg- 

 stage, however, only lasts about a fortnight, although the larva3 feed 

 very little (or not at all) on Viola canina before hybernation. 



Autumnal females of Colias edusa, enclosed on a growing plant of 

 Trifolium repens, Lotus corniculatus, etc., placed in the sun, and supplied 

 with a little honey and water for food, will lay their eggs pretty freely 

 so long as the weather is bright and sunny. 



Captured females of Colias hyale will lay their eggs on Trifolium 

 repens, Medicago hqmlina, M. sativa, etc., in August. They hatch in 

 about a fortnight, and the young larvae feed up slowly to hybernation. 



These are only a few "hints" extracted from our work Practical 

 Hints for the Field Lepidopterist, and are simply inserted as illustrations 

 of the details to which the attention of the seeker for eggs of lepidoptera 

 must be directed. 



CHAPTER VI. 



BUTTERFLY LARViE AND THEIR MOULTINGS. 



The newly-hatched larvae of many families of butterflies are very 

 similar to each other, much more so in many cases than are the 

 newly-hatched and adult larvae of the same species. The term 

 "embryonic" has been applied to newly-hatched larvae in their first 

 instar or plumage, i.e., before their first moult, and the term is a 

 happy one, because, structurally, the larva until this moult retains all 

 the characters that the embryouic larva possesses just before it leaves the 

 egg. This stage rarely lasts more than a few days (although Dry as paphia 

 and Argynnis aglaia are both reputed to have larvae that leave the eggs 

 in August, and, without feeding, remain in this state till the following 

 March). The marked peculiarity of many newly-hatched lepidopterous 

 larvae is the similarity in the position and arrangement of certain 

 little chitinous buttons or knobs, each bearing a conspicuous hair or 

 seta ; these buttons, with their setae, are known as the primary 

 tubercles. This similarity the young butterfly larva shares, with 

 scarcely any modification, with the larvae of most other lepidopterous 

 superfamilies, and, as we know that the embryonic stages often 

 recapitulate the past history of the development of the species, we 

 speak of this general or common form of butterfly larvae as a 

 generalised type, and consider it as exhibiting, more nearly than the 

 adult larvae, a primitive or ancestral form of the butterfly caterpillar. 

 With the first (or, at latest, the second) moult a very considerable 

 change takes place, and the larva becomes more specialised. 



The larvae of our butterflies live more or less exposed on their food- 

 plants ; their enemies are numerous, and they are sought eagerly by 

 various animals as food. Their colours, hairs, etc., are so modified as 

 to make them difficult of detection on their foodplant in their normal 

 position of rest, or by making them unpalatable if they be detected. 

 Hence the larva of each species is so far modified or specialised in the 

 direction of its colour and markings, or in its armature — spines, hairs, 



