171 



July, the female being not at all broken and very little worn, 

 evidently not many days from chrysalis. On 1 August these 

 began to hatch. On morning of 12th two larvse suspended, and 

 at 4 p. m. of the same day were in chrysalis, and the butter- 

 flies emerged 20 August. The several stages were ; egg, 2 to 

 3 days ; larva 11, chrysalis 8. Whole period 21 to 22 days. 

 As the larva, from 2.5 mm. at hatching, reaches 4.6 mm. at 

 maturity, this was rapid growth. 



Another brood of larvtc, however, raised in May 1876, ma- 

 tured about as rapidly as those of August 1878, and the chrys- 

 alis much more so. The eggs were laid 14 May, hatched the 

 17th ; the first moult passed the 19th ; second moult the 21st ; 

 two passed the third moult on the 22d ; these two passed the 

 fourth moult on the 25th ; one of them made chrysalis the 

 29th, and its butterfly emerged 1 June. The whole period 

 was but 17 days from the laying of the egg to the emerging of 

 the butterfly ; the egg 3, larva 12, chrysalis 2. Here the 

 chrysalis stage was immensely accelerated by the hot weather 

 which then prevailed, the mercury ranging daily between 29° 

 and 32° C. 



The fourth brood of larvae of 1878 proceeded from eggs laid 

 30 August, and the butterflies from them began to emero;e 29 

 September. Whole period 30 days. 



These four broods may fairly be taken to represent the usual 

 sequence of generations in this region, for though the butter- 

 flies of the first, as I bred them, appeared 30 May, while the 

 eggs of the second were laid 1 June, yet fresh butterflies were 

 seen flying nine days before SO May, and besides it is not likely 

 that I saw the flrst that were on the wing. Individuals may 

 have been out some days earlier. On the other hand, the in- 

 terval between the butterflies of my second brood and the lay- 

 ing of eggs for the third was 34 days. Between the butterflies 

 of the third and the laying of eggs for the fourth was but 5 

 days. But butterflies fresh from chrysalis were seen late in 

 October, sOme weeks after my fourth had emerged. So that 

 between the laying of eggs in early spring and the end of the 

 season, there is ample time for a sequence of at least four gen- 

 erations of butterflies. When the female emerges from chrys- 



