THE VICTORIAN NATURALIST. 



69 



Head and thorax of 

 A. eucalypti. 



arrived at by the learned authors mentioned, and apparently but 

 little advance has been made up to the present. Reaumur, how- 

 ever, was right when he said the threads were cut or broken, 

 though altogether wrong in suggesting that it was the eyes of the 

 moth that were used in the operation. 



If we look at a specimen of Anthercea eucalypti we observe that 

 the head is very small, and the thorax 

 almost truncate — in fact, nothing less 

 likely to serve as a wedge can well be 

 imagined. The moth is very common; 

 most entomologists here must have bred 

 it, and many doubtless are familiar with 

 the chipping or tearing sound which may 

 be heard for some time previous to the 

 moth's appearance. Now, this tearing 

 sound and evident strenuous exertion 

 for a period extending over two or more hours is hardly consistent 

 with the acid theory and the "gentle effort required to push down 

 what was previously so strong a barrier." Moreover, as far as I 

 have been able to experiment, the Antherea does not emit any fluid 

 capable of softening the cocoon. I have tried the fluid invariably 

 found in the cocoon after emergence, upon various parts of it, 

 but with no effect ; neither is it affected by hot water or chloro- 

 form. 



It might be thought possible for the insect to carve a way out 

 by means of its claws, but the position of the legs precludes their 

 being of any use, as there is not room enough to allow of their 

 action. It is to the wings we have to look for an explanation of 

 the mystery. 



On the primaries, where the nervures con- 

 verge together at the base, may be found a 

 sickle-shaped projection, sharp at the point and 

 extremely hard ; it is with these instruments, on 

 either side, that the enclosed moth effects its 

 deliverance. 



When ready to emerge, the insect by move- 

 ments of the wings and legs bursts the upper 

 portion of the pupa case into small fragments, 

 which are then worked downwards, leaving the 

 insect free to commence its attack upon the 

 walls of its prison. 



At first a series of longitudinal scratches 

 are made, which eventually convert the smooth 

 inside of the cocoon at the top into a 

 mass of tangled fibre ; this has the effect of thinning the 

 walls, and also of giving a better hold to the insect in its next 

 and most important operation of cutting out a circular opening 



Moth before 

 emergence, show- 

 ing sickles in 

 position. 



