318 BRITISH LEPIDOPTERA. 



Ovum. — The form differs from a regular ovoid ; it has three 

 different diameters — the micropylar axis 2 -2 mm., a longer 

 secondary axis i'53mm., and a shorter i'36mm. Looking down 

 on the micropylar end, the egg is elliptical, with the diameters, 

 i*53mm. and i^mm. This corresponds to a section one-third 

 (•7mm.) distant from the micropylar end ; the egg is, however, 

 ovoid, and not elliptical in longitudinal section, i.e., it tapers 

 towards the micropylar nadir and one-fourth distance ('55mm.) 

 from the end opposite to the micropyle, the elliptical section would 

 have diameters 1*22 and riomm. ; this is not quite all as the egg 

 is not quite straight but one side is slightly flattened, the opposite 

 a little rounded (this form is one very common in Geometrids, also 

 in Drepanids). The surface of the egg is so clouded with brown 

 gum that its colour is thereby dominated. Really the egg is white 

 but not quite densely enough to obscure the green contents. I 

 succeeded in chipping and scraping off some of the gum revealing 

 a smooth surface, with faint pentagonal and hexagonal netting, 

 not definitely rising above the surface, this netting was a little 

 finer just round the micropyle, but without any obvious rosette of 

 very fine netting. The micropyle was in a slightly paler area of 

 egg (or egg contents). Many of the eggs showed a definite dark 

 spot at the micropyle, as this is not constant and did not appear in 

 the cleaned egg, it must be some effect of the gummy coating at 

 this spot (Chapman, May 13th, 1899). Greyish-green in colour 

 (but thickly embedded in brown gum) • rather over 2mm. long, 

 and i*3mm. x I'imin. along other axes ; a very marked oval 

 depression on upper surface (considering the eggs to be laid upon 

 each other), the shell without an obviously distinct reticulation, ex- 

 ceedingly roughened by raised points ; the micropylar area conspicuous 

 as a minute black point placed at the rather broader end of egg, 

 very slightly depressed (Tutt. Described May 5th, 1899, from eggs 

 laid April 22nd, 1899, near Knutsford). Another batch was pale 

 whitish-green in colour with scarcely any of the thick brown gum 

 that characterises most of the batches ; in these the micropyle was 

 very distinctly made out even with a hand lens, the central black 

 point being surrounded by a very clear white ring (From Mrs. Cowl, 

 Bournemouth, May 17th, 1899 ; these hatched May 25th, 1899). 

 Another batch, colour pale olive -brown, the micropylar area 

 rather dark, the micropyle a very minute depression at the apex, 

 paler than the surrounding area. The surface is practically smooth, 

 a slight roughness under a fairly high power does not resolve into any 

 definite reticulation (eggs from Pitcaple, May 8th, 1899). When first 

 laid the eggs are of a paler and greener tint than they afterwards 

 become, but after deposition they change colour in a few minutes 

 (Reid). When first laid the eggs are covered with a sticky 

 substance by which they are attached and which makes them appear 

 dark green ; they soon dry and are then bluish-white and opaque 

 (Burraud). Reaumur describes the eggs as like " des grains d'un e'mail 

 blanc un peu bleuatre, ou d'une porcelaine dont le blanc peche 

 pour etre trop bleu " {Mem., i., p. 631). 



Habits of larva. — The young larvae live gregariously, and 

 do not separate to any extent until after the third moult. Poulton 

 notes that, in the first stage, larvae in his possession not only showed 



