EDWARDSIA W- ALBUM. 153 



whitish or putty colour, and firmly attached to the bark by the under- 

 side, remaining thus all the winter ; the shell resembles porcelain in 

 appearance, is insoluble in water, resists any amount of wet, and also 

 effectually preserves the contained larva from the effect of frost or 

 other climatic influences. We note (Ent. Rec, ix., p. 292) that 

 the eggs are laid above, or directly below, an aborted leaf-bud, and 

 harmonise so exactly with the colour of the elm-twig on which they 

 are placed, that only an entomologist could possibly detect them. 

 They appear to be placed on the old, and not on the growing, twigs, and 

 are laid either in couples or singly. McDunnough observes that, in 

 July 1906, he sleeved a couple of £ s, and found that they laid eggs 

 without difficulty when placed in the sun in a glass jar containing elm 

 twigs. The ova were deposited (usually singly) at base of bud, 

 although at times up to twelve were deposited in a group around twig. 

 The rate was five to six per day, and each 2 continued laying during a 

 period of two weeks, kept alive on sugar and water. The larva makes 

 its escape through the micropylar area by means of a regular and 

 circular hole, the remainder of the egg-shell not being eaten. 



Ovum. — Eepresented pi. ii., fig. 4 (two different views, one from above 

 and the other lateral). Kemarkable in appearance, owing to a prominent 

 whitish belt that runs round its equator (or, rather, base). A side view 

 gives a distinct idea, even under a lens of moderate power, that it is 

 minutely hairy. Looked at from above, the egg presents the appear- 

 ance of a whitish rim, extending beyond a dark central portion, which 

 is heaped up cone-like, but flattened on the top with a circular 

 depression at the apex [like a jam-tart with a prominent crust, the 

 jam heaped-up centrally, and then flattened on the top] . The white 

 rim consists of the upper (and protruding) layers of pointed cells, of 

 which the basal portion (or sides) is formed, the lower rings of these 

 cells decreasing in size until the point of attachment is reached, the 

 whole forming a shallow basin in which the central part of the egg is 

 placed. The central part of the egg forms a flat truncated cone, dark 

 reddish in colour, minutely pitted, and suggesting towards the lower 

 part of the cone a polygonal structure. A large number of points also 

 arise from the surface, and there is a suspicion that these bear minute 

 hairs. The micropylar area is very conspicuous and well-defined. 

 It consists of a circular basin, in the centre of the flattened apex, 

 the sides of the hollow almost perpendicular, the micropyle proper 

 appearing as a minute depression in the centre of its base, and sur- 

 rounded by concentric rings of tiny cells (Tutt, July 17th, 1897). 

 Rayward doubts whether the living egg is ever really reddish in 

 colour. He observes that, of some 25 eggs taken by himself last 

 autumn (1906), all — with, he thinks, two exceptions — were leaden-grey; 

 the exceptions were leaden-black, and these eggs failed to hatch. In 

 none was there any apparent shade of red. Just before hatching, 

 the egg changes slightly in appearance, becoming lighter in 

 colour probably due to the larval skin being removed from contact 

 with the inside of the shell (in lift., May 9th, 1907). The shell is 

 very translucent, though not transparent. The egg is not simply bun- 

 shaped, but below the widest flange-like margin, it is full below, some- 

 thing after the fashion of the egg of Centra erminia. The width is 

 , 84mm., the height 0'26mm., from apparent margin, but about 

 0-38mm. if the lower protuberance be got into view. The simple bun- 



