PI KRIS RAPiE. 153 



these became pupae between July 15th and 23rd, and 

 the butterflies were bred between the 21st and 27th ; at 

 this last date there came plenty of females of the second 

 flight, and I found eggs from time to time up to Sep- 

 tember 8th ; and from the earliest of these eggs, found 

 at the end of July, I reared the larvae and bred several 

 butterflies at the end of September and through October, 

 thus obtaining a partial third flight ; the greater part 

 of my pupae, however, remain over for next spring. 

 During the warm weather the larva seems to be hatched 

 about six days after the egg is laid ; the moults are 

 not easy to detect because the change of colour is 

 slight and the larva eats the cast skin, but I believe 

 there are four moults at intervals of about four or five 

 days each, and the pupa is developed in five or six days' 

 time from the fourth moult. I have found the eggs on 

 Tropoeolum majus and canariense, cabbage, charlock, 

 mignonette, and horse-radish ; to these plants Mr. 

 Harwood adds hedge mustard (Sisymbrium officinale) 

 and watercress. 



The egg is laid singly (sometimes a leaf in a favourite 

 corner will get three or four eggs left on it, but each 

 deposited separately), standing on end, and is flask- 

 shaped or skittle-shaped, being just 1 mm. in height, 

 rather more than ^ mm. wide and about -g- mm. across 

 the top ; with eleven, twelve, or thirteen longitudinal 

 ribs, coming up evenly and neatly to the apex (one of 

 the distinctions between this species and napi), with 

 delicate even transverse reticulation. The colour at 

 first is very pale greenish-yellow, afterwards becoming 

 more yellow, some even orange-yellow. The young 

 larva eats the empty shell, and in several cases I 

 found larva?, which had hatched in my pill boxes, 

 after eating their own eggshells attacking and 

 devouring their neighbours who were yet unhatched ; 

 of course this was done in the absence of proper food, 

 and would hardly occur in nature, but I do not remember 

 to have seen such a thing among all the hundreds of 

 other species I have reared from the egg t I have seen 



