13 



soldiers, in consequence of which, on hatching, those caterpillars which pro- 

 ceed from the upper end, cannot disturb the adjoining eggs. These cater- 

 pillars scale walls and even glass windows without difficulty ; but in the last 

 instance, if the square upon which the creature is travelling, be examined 

 with a microscope, a visible tract like that of a snail may be seen. This con- 

 sists of little silken threads, which it has spun in a zig-zag direction, forming 

 a rope ladder, by which it can ascend a surface it could uot otherwise adhere 

 to. These threads being of a gummy nature, harden in the air, and easily 

 attach themselves to the glass." — Miss Jermyn's " Vade Mecum." 



The chrysalis is pale green, dotted with black. Bonnet states " that the 

 chrysalids exposed to a frost of 14° R. below zero (C. ' V F.) became lumps of 

 ice, and yet produced butterflies." There are two or three varieties of colour, 

 of which the above is the commonest, Another variety is bluish green all 

 over, with yellow ridges and spiracles, with the black spots much smaller and 

 fewer in number. Another variety is mottled with the green and white tints. 



This species is very subject to the attack of a Hymenopterous parasite — 

 Ajjanteles glomeratus — concerning which is an interesting note in the " Maga- 

 zine of Natural History," Yol. 3. : — " On the 28th of June, I put twenty 

 caterpillars of the large cabbage white butterfly, into a wire cage, they were 

 mostly full-sized, and continued to feed on cabbage leaves placed in the cage 

 with them. On the following day, five or six of the largest left the leaves, 

 and crawled about the sides of the cage during the rest of the day. The 

 next morning, June 30th, I found them resting on large clusters of minute 

 cocoons of an ovate form, the largest not exceeding two lines in length, and 

 about the thickness of a caraway seed. Each one was enveloped with a fine 

 yellow silk, resembling that of the common silkworm. On these clusters the 

 caterpillars remained the whole day without moving. Fresh leaves were 

 given to the rest, but in the course of this day they all left oft" feeding, 

 crawled about the cage, but underwent no other change. The next day I 

 found they had ejected the parasitical progeny they had been impregnated 

 with, and like the preceeding, continued resting on the clusters they bad 

 formed, and the last operation of these devoted caterpillars was to envelope 

 each cluster in a veil, formed of the most delicate web. Some of them ex- 

 ecuted the task, but the greater part were too feeble to complete it, and in 

 the course of three days more, they became motionless, and gradually one 

 after another fell to the bottom of the cage, exhausted and shrivelled. The 

 clusters of cocoons varied in their number, some contained upwards of a 

 hundred, others not more than sixty or seventy. On July 12th, the first- 

 formed cluster of cocoons evinced a state of maturity, and in the course of 

 the day, numbers of the perfect insect came forth. Their exclusion was 



