STRYMON PRUNI. 201 



Edwardsia w-album,, they might easily be mistaken for one of the 

 dormant, or half-dormant, buds, common in this situation ; there were 

 no specimens on the smooth bark of a twig between the nodes. On 

 the more slender wood of the sloe, they select an older portion of 

 wood than is done by, say, Bithys quercits, which, on the more robust 

 oak- shoots, often places its eggs amongst the buds for the coming spring 

 (Chapman). The egg is laid on the twigs of Pr units spinosa, and remains 

 attached thereto all the winter (Newman). In confinement, living 

 2 s sleeved on a plum or sloe bush, if the gauze be sprinkled with 

 water, will lay freely (N. C. Eothschild). Lambillion notes that the 

 eggs are laid in July on the twigs of plum and of sloe in Belgium. 



Ovum. — The egg is round and flat; - 75mm. in diameter, - 36mm. 

 in height. Seen from the side, the ends are rounded, not quite in a 

 semicircle, as the lower margin is less rounded than the top, or perhaps 

 more clearly, taking the top and bottom to be parallel, the bottom is 

 longer (i.e., wider) than the top. The top and bottom are so nearly 

 parallel that, at 0*1 5mm. from either end, the height is 035mm., and 

 it is not -40mm. at the middle. Seen from above, however, it is observed 

 that the top is by no means flat ; the egg rises dome-like to 0'25mm. 

 from the margin, and at once curves down again to a deep central 

 hollow, 0-25mm. across. The egg is interlaced all over by a mesh of 

 raised ribs in triangular patterns (six triangles being often regular enough 

 to form a good hexagon), a little irregular in places, but so that a direct 

 line of ribs can often be traced diagonally from the top to the bottom 

 of the egg. Each triangle is about OOBmm. along each side, where 

 they are largest round the margin of the egg. They become smaller 

 upwards and towards the centre, and, in the hollow on top, are very 

 small and fine, and hardly discernible centrally, where there appears to 

 be a slight elevation. At each intersection of ribs (or meeting-place 

 of usually six, sometimes fewer, ribs) there rises a short column. 

 These are evanescent in the hollow on top, very short round it, and are 

 only fully developed round the sides, where they are nearly as high as 

 the sides of the triangles are long; their summits expand and are 

 notched into six beads with a central hollow. The less well-developed 

 columns have the summit structure less fully displayed. The real 

 arrangement of the surface would perhaps be more correctly described 

 if we began with these columns each in its place, and then described 

 the connecting ribs as hanging from one to another in catenary curves, 

 and the egg-surface between the ribs as similarly hanging inwards from 

 the ribs. Pictured in this way, the elegance of the whole arrangement 

 may be more fully realised. The materials of the eggshell appear to 

 be bright brown, as is evident when columns or ribs are got as trans- 

 parent objects in profile, but the interior contents (larva ?) seem of a 

 leaden colour, so that the colour of the egg, as a whole, is somewhat 

 darker and greyer than a nut-brown (Chapman, December 23rd, 1905). 



Habits of larva. — Very little is known of the young larva. Of 

 one that hatched out of an egg on March 4th, 1906, Chapman 

 writes — "March 4cth: Larva hatched on this date, began to eat 

 petals of a plum-flower (Prunus myrobalus). March 5th : Small 

 larva seems restless and dissatisfied, and will not look at flowers, 

 leaves, or unopened buds of sloe ; makes, however, a little frass. 

 March 6th: Has eaten a small hole into a slightly expanded bud, 

 and made some " frass." It is a curious lumbering awkward 



