110 THE ENTOMOL,OGISt's RECORD. 



10 a.m. and ended at 3 p.m. Fruitful pairings have frequently- 

 occurred in temperatures of 40°F.-50°F. ; and in several cases at 33°F. 



2. Ovulation. — -Unimpregnated $ s almost invariably deposit ova 

 5-12 days after emergence. An impregnated ? usually deposits about 

 100 ova during the night following impregnation, and repeats the 

 process within the next 24 hours. A large chip pill box was used for 

 ovulation, and most ? s were satisfied to lay their ova on its sides or 

 lid, but some preferred the small twigs which were always placed in 

 the box. The 2 s were usually killed as soon as 100 ova were laid, in 

 order to retain them in good condition, but if allowed to live in some 

 cases 400-500 ova were deposited, and in one case 585 were noted. In 

 gauze cages, the gauze was commonly used as a place for oviposition. 

 Glass also often served. 



Both sexes accepted moistened lump sugar as refreshment in the 

 intervals of their marital duties. 



3. Ova. — Pale yellow when laid ; if fertile, becoming bronze in 3-8 

 days, according to temperature. Hatching occurs in 15-84 days, 

 according to temperature. In ordinary April and May weather 22 

 days. The bronze colour deepens and becomes dusky 36-24 hours 

 before hatching. Ova were kept in glass topped tin boxes. Hatching 

 is usually spread over 2-5 days. Introduction of even a single leaf 

 before hatching is fatal to the ova, presumably this is due to the 

 moisture. 



4. Larva' on liatchimj take no further notice of the egg-shell, but 

 are very active, and walk round ceaselessly till the}^ find a pabulum. 

 Of one batch, which after hatching was forgotten for 72 hours, nearly 

 all were found to be alive. The larvfe were kept in glass topped tin 

 boxes for the first few days, or even few weeks, of their existence. If 

 direct sunlight is prevented from falling on the boxes the mortality is 

 extremely low. Throughout the experiment, of all the larvje which 

 hatched less than 5% died from disease. 



5. Lenijth of larval life.— In the single case where forcing was 

 tried, hatching to cocoon formation occupied 41-64 days. Under 

 apparently natural conditions the shortest was May 3rd-June 20th. 



Much depends on the foodplant. 



6. Food-plant. — Privet, especially the evergreen variety, and apple, 

 are the best food-plants. They promote more rapid growth in the 

 larva? than ivy, pear, plum, sallow, birch, hawthorn, Prioms /lii^sardU, 

 willow, poplar, travellers' joy, which also form useful food-plants. 

 Broom produced but very slow growth, but all lived. 



7. Ca;ics.- — In addition to 



(a) Ordinari/ breedimf cages, epecially that special variety which 

 ■each collector has evolved for his own use, and secretly considers the 

 best on earth. 



(b) Biscuit tins, half-size, were found to be most useful, giving a 

 minimum of trouble, occupying so little space, and cheap, and above 

 all healthy, as might hardly be expected, and, moreover, repeated 



