VI. THE PSYCHINA. 125 



over a twig, the ends being joined to the upper edges of the case on each side ; in this 

 way it hangs suspended, the caterpillar lying snugly within. I have often known a 

 larva to remain thus for over three weeks without moving, and afterwards resume feeding 

 as before ; this probably occurs whilst the inmate is engaged in changing its skin. At 

 night the larvae may be seen busily engaged : they project the head and first four 

 segments of the body beyond the case, and walk about with considerable rapidity, often 

 lowering themselves by means of silken threads ; the only locomotive organs are, of 

 course, their strong thoracic legs, which appear to easily fulfil their double function of 

 moving both larva and case. If disturbed, these insects at once retreat into their cases, 

 closing the anterior aperture with a silken cord, which is kept in readiness for the 

 purpose, and pulled from the inside by the retreating larva. This operation is most 

 rapidly performed, as the upper edges of the case are flexible, and thus fold closely 

 together, completely obstructing the entrance. When full grown, this caterpillar fastens 

 its case to a branch with a loop of strong silk, which is drawn very tight, preventing the 

 case from swinging when the plant is moved by the wind, and also rendering the insect's 

 habitation more inconspicuous, by causing it to resemble a broken twig. The anterior 

 aperture is completely closed, the loose edges being drawn together and fastened like a 

 bag. The posterior end of the case is twisted up for some little distance above the 

 extremity, thus completely closing the opening there situated. It is lined inside with 

 a layer of very soft silk spun loosely over the sides, and partly filling up each end. 

 In the centre of this the pupa lies with its head towards the lower portion of the case, 

 the old larval skin being thrust backwards amongst the loose silk above the insect. 



The male and female pup;e may very easily be distinguished. The male pupa is 

 rather attenuated, and has all the organs of the future moth plainly indicated on the 

 integument, as is usual with lepidopterous pupte. The female pupa, on the contrary, is 

 merely a chain, of segments, with a few faint indications of rudimentary organs on the 

 anterior extremity. It is, moreover, much larger than the male pupa. 



The insect remains in this condition during the winter months. About September 

 the male pupa works its way down to the lower end of the case, forces open the old 

 aperture there situated, and projects the head and thorax, the pupa being secured from 

 falling by the spines on its posterior segments, which retain a firm hold in the silk. Its 

 anterior portion then breaks open, and the moth makes its escape, clinging to the 

 outside of its old habitation, and drying its wings. 



The perfect insect must be about from September till December, but I have never 

 then observed it. The only specimen I have seen was noticed flying very rapidly in the 

 street in Wellington, in July. I was at first unable to tell what species it was, as it had 

 a most unusual appearance on the wing, but its subsequent near approach enabled me.- 

 to ascertain for certain that it was a specimen of this insect. In captivity I have also 

 noticed the extreme activity of the male when first emerged. Indeed this moth is so 

 vivacious, that it often happens, owing to the emergence usually taking place very early 

 in the morning, that specimens are more or less injured by their efforts to'escape, before 

 they are discovered in the breeding cage. This restless energy of the male is no doubt 

 essential to the insect's well-being, as the females, hidden away in their cases and 

 incapable of any movement, must of necessity be very hard to discover. The power of 

 locomotion lost in the one sex is thus doubled in the other. Considering the protection 



