78o 



THE NATURE BOOK 



highly probable that the spark of life 

 within its frail structure had by that 

 time succumbed to the large demands 

 made upon it, for it is seldom that the 

 insect lives for many hours after depositing 

 its numerous eggs. However, the safety 

 of her species was ensured. The tiny and 

 prettily decorated eggs, which she had 

 placed so carefully and systematically 

 amongst the leaves, were now bursting 

 open, and from each broken shell emerged 

 a little caterpillar — a baby Painted Lad\' ! 



WHEN FOUR WEEKS OLD THEY WERE 

 FULL GROWN. 



These insect infants were grej^ish in 

 colour, with rather large, shiny black 

 heads, and covered with short bristles, 

 and, of course, were very tiny when they 

 first appeared. They soon proceeded to 

 business, and made inroads into the soft 

 parts of the leaves, and, at the end of a 

 fortnight, their bodies darkened in colour, 

 and they became conspicuous about the 

 food plants (see p. 779). A week later 

 still, they were exceedingly busy, and 

 swarmed about the nettles ; and the 

 following week (July loth) the caterpillars 

 were full grown. They were then any- 

 thing but handsome, their only decoration 

 being some yellowish markings about their 



bodies ; but not the slightest indication 

 was visible that they were presently to 

 become lovely butterflies. 



Eventually, one of the larvae stopped 

 feeding, and, after carefully selecting a suit- 

 able site beneath a leaf-stalk, it slowly 

 proceeded to spin a silken pad or cushion 

 to it, finally attaching itself to this cushion 

 by its tail claspers. In this way it 

 suspended itself upside down, and there 

 it hung a most dejected-looking object 

 (p. 781). After it had been so hanging 

 for a few hours, it commenced to squirm 

 and wriggle its body, when its skin near 

 the back of its head suddenly burst open. 

 Then the caterpillar moulted its skin, for 

 as the body wriggled the skin slowly 

 shrunk up towards its tail-end, where it 

 was attached to the silken cushion. The 

 second illustration on page 781 shows this 

 process taking place, just at the half-way 

 stage. At the end of four minutes the 

 shrunken skin was free, but it could not 

 yet fall away, for it still had to be freed at 

 the point of attachment to the stem. 

 Presently, though, the developing insect 

 detached itself, let the skin drop to the 

 ground, and then re-attached itself to the 

 silken pad (p. 7S1). This seems a very 

 extraordinary feat, for, apparently, the 

 insect must loosen its hold while allowing 

 its cast skin to fall. However, close 

 examination shows that at the extremity 

 of the body are numerous minute hooks 

 by means of which the insect attaches 

 itself to the silken pad. It therefore 

 probably detaches some of the hooks 

 while the others remain connected, and 

 so the skin is gradually passed over the 

 point of attachment and falls to the 

 ground. We no longer, then, have a cater- 

 pillar to consider, but a pupa, or chrysalis 

 — the next stage of the insect's develop- 

 ment. 



The chrysalis is at first of a greyish 

 colour, but when it has been hanging for 

 a few hours its angles become burnished, 

 and it then presents metallic shades of 

 various hues — green, crimson, gold, and 

 silver, according to the position from which 

 It is viewed. 



On July nth two larvcT became chrys- 

 alides at almost the same time beneath 

 the cleaned central vein of a thistle leaf 

 on which they had been feeding (p. yi>2), 

 and there these pupiv hung motionless 



