in Pediijree MotJc-bi-ecdinij. 87 



40 for forcing at about TS"" — 80", and similarly con- 

 stituted batches of 40 for bottling and sleeving re- 

 spectively. 



Of the forced, 35 hatched from 21st to 29th May, and 

 29 emerged between 4th and 18th July, none cripples. 

 The forcing began 21st May, when the first egg hatched, 

 and of these I have a tolerably perfect record, having 

 taken the spun-np ones almost every day from the time 

 they began to spin — 17th June — till they finished — 1st 

 July — and having recorded in the case of each pupa the 

 date of S2)inning and of emergence. There were 

 15 males and 14 females. The larval period averaged 

 29'8 days, the range apparently being from 27 to 34 

 days, or more. The pupal period was as follows : — 

 Males, average 16"37 days, range 13 to 18 days ; females, 

 average 15'32 days, range 14 to 17 days ; average of 

 both 15'86 days. (Pupal period with me commences 

 with the spinning-up, owing to the difficulty of 

 ascertaining when actual pupation begins with a larva 

 that is enclosed in a cocoon. The actual pupal period 

 is therefore several days shorter than that given by me ; 

 by 4 or 5 days in the sleeved pupa of autumnaria, and 

 the larval period is lengthened in a corresponding 

 degree). 



The bottled were not so well attended to as the rest ; 

 whether for that reason or not, only 12 emerged, one of 

 which was a cripple, out of 35 hatched between 21st 

 ]\Iay and 4th June. They were kept as larvae on a 

 table near the window, which generally stood open, and 

 as they spun up were transferred to a tray at the other 

 end of the room. About 24 spun up between 7th July 

 and 10th August. The pupae were forced from 12th 

 August (at which time 3 had emerged), and the moths 

 appeared from about 6th to 27th August, 7 males and 

 5 females, of which one was crippled. As nearly as 

 I can get at them, the larval and pupal periods together 

 averaged between 70 and 80 days, of which the pupal 

 seems to have been about 30 in the males and 28 in the 

 females ; about 29 j in both sexes taken together. 



Of the sleeved about 30 eggs hatched from 21st Ma}- 

 to 4th June. During this period they were kept on the 

 table above referred to. On the 5th they were t.rans- 

 f erred to a sleeve on a dwarf birch-tree in the garden, 

 which is a cool one ; 27 spun up from about 24tli July, 



