Insects' Eggs. 329 



uniformly covered with imbricated scales, and is terminated in 

 the upper pole by a geometrical series, which fold in towards 

 the micropyle. In every instance the worm eats its way out 

 of the side of the egg ; the aperture is shown in the drawing ; 

 this moth appears to cover her eggs with fine hairs, and the 

 empty spherical egg cases are beautifully iridescent. The egg 

 of the small Emerald Volute moth (Jodis vemaria), Fig. 16, is 

 remarkable in form, which is somewhat oval, but flattened on the 

 broad side, of silvery whiteness, covered with minute reticula- 

 tions and dots, peculiarly translucent, so much so that the little 

 yellow-brown worm is seen curled up within, as shown in the 

 egg to the left. At first it appears difficult to detect the pre- 

 sence of either lid or micropyle, and it is not until after the 

 worm has eaten its way out that you clearly see at which end it 

 was placed. The aperture through which it has made its 

 escape is shown in the egg to the right. As to the change 

 of colour (which occurs from physiological causes), connected 

 with the development of the embryo, a remarkable instance is 

 afforded, and one from which the insect partly derives its 

 name, in the Grlory of Kent (Endromus versicolor) . The egg 

 is first bright yellow, then successively green, rose colour, and 

 reddish black. A still more familiar instance is presented in 

 the egg of the Silkworm moth (Bombyx mori), Fig. 11, which 

 when first laid is of a delicate pale yellow, this hue it retains for 

 some time, it is subsequently of a reddish brown, and just 

 before the embryo quits the egg it acquires a slate colour, par- 

 taking for the time being of the colour of the embryo within ; 

 but so soon as the worm emerges forth, the shell regains its 

 original pale yellow. The micropyle, if that can be so called, 

 which in this egg is a raised nipple, is in the more flattened pole 

 of the egg. The mouth of the young worm lies towards the 

 horn of the crescent of that pole, and it is at this point the 

 first cut is made, just sufficient of the membrane is eaten 

 away to admit of the head and body passing through the aper- 

 ture. The outer and inner portions of the egg membrane are 

 represented magnified 150 diameters at a and b, Fig. 11. 



The egg of the small Silver-lines moth (Hylojohila prasi- 

 nana), Fig 9, is yellow brown, in form a truncated pyramid. 

 The micropyle is enclosed in a regular series of radiating lines. 

 A series of raised ribs are set in regular order around the sides, 

 and the cross bars which connect them. These present a 

 pretty basket-like pattern. The egg is flattened out at the 

 base, apparently for the purpose of securing it more firmly to 

 the leaf. The Meadow-brown butterfly {Ejnnephile janira), 

 Fig. 14, lays a sub-conical egg, considerably flattened towards 

 the apex, the raised ribs which stand away from the sides have 

 a silvery colour, and give to the whole a corrugated appearance. 



