440 



BRITISH BUTTERFLIES. 



are much wrinkled, and it is difficult to make out their contour. The 

 basal portion of the shell of the egg is evidently very plastic when the 

 egg is first laid, as when the egg is detached from the leaf, the base 

 shows a replica of the leaf-surface in which the stomata of the leaf are 

 often very clearly represented. The colour of the upper part of the 

 egg is pale brown, with a pink tinge; the base beneath is pale grey 

 (Sich, July 31st, 1906). The egg forms a segment of a sphere, about 

 •63mm. diameter at the base, and -31mm. perpendicular height. The 

 surface is covered with cells or pits. At the apex is the large micro- 

 pylar depression, from the edge of which six rows of cells run down- 

 wards, and between which are six well-developed ribs. Each row of 

 pits consists of three large cells of different size, the uppermost one the 

 smallest, the lowest the largest ; similarly, with their depth, the upper is 

 the most shallow. The micropylar cell is, as a result, surrounded by 

 six smaller cells. The sides and floors of the cells appear to be 

 minutely dotted, also the border of the base where the six ribs ter- 

 minate. The colour of the egg is whitish, but before hatching it 

 changes slightly, and becomes somewhat tinged with flesh-colour 

 (Gillmer). 



Habits of larva. — Some eggs laid June 12th-13th, 1892, at 

 Budafok, hatched June 20th, the larva? were brought to England, and 

 by the 28th the number was reduced to five; they were put on a dock, 

 probably Rumex crispus, and kept in a sunny greenhouse, where three 

 reached maturity, the first pupating on July 24th, another on the 

 30th, the third on the 31st. The imagines emerged between August 

 9th-17th of the same year (Nicholson). In the Berlin district, 

 the larvae leave the eggs in July and hybernate after the 

 third moult, feeding up again in spring and becoming fullfed 

 about the middle of June, although, sometimes, they are not fullfed 

 until August, e.g., on July 12th, 1905, several three-quarter grown 

 larvae were found which grew rapidly and produced the first imago, 

 a 2 , on August 18th, 1905. In the middle of August the same year, 

 Fassl had larvae from eggs of the year, still very small. The larva 

 has a snail-like crawl, and lives on the underside of the leaves of 

 Rumex hydrolapathum, from which it first gnaws off the epidermis, 

 but, as it gets larger, it eats little holes right through the leaves. * 

 Locke notes [Sac. tint., iii., pp. 12-13) that, about the end of April, on 

 the underside of leaves of Rumex, he always found the larvae in couples, 

 never more on one leaf, and that these always produced a $ and a £ . 

 The suggestion underlying this assertion is, one suspects, quite unten- 

 able (Gillmer). On June 8th, 1906, we received, through the kindness 

 of Mr. Gillmer, larvae which were variously distributed. These were 

 nearly, or quite, fullfed, and, at rest, looked at ventrally, the head is 

 drawn into the prothorax so as to be, on the ventral side, almost 

 invisible, the prolegs are of a rather paler tint than the ground colour 

 of the venter, and the still paler feet are pushed out prominently to 

 clasp the object on which the larva rests. The body is drawn down flatly 

 against the resting-surface, and the reddish-brown hairs form a sort 



* In confinement, plants of Rumex hydrolapathum, R. sanguineus, or R. 

 aquaticux, should be potted up, as the leaves of these plants, placed in water, are 

 useless as food after one or two days. The larvae should be sleeved or put into 

 tightly-fitting breeding-cages, as they escape through the smallest cracks as soon 

 as the food fails (Gillmer). 



