174 INSECT TRANSFORMATIONS. 



ner skin, — those on the fore part of the hody laid to- 

 wards the head, and from the tburth ring backwards in 

 a contrary dnection. 



Swammerdam, R aiimur, and other natnrahsts, re- 

 peatedly tried the experiment of cutting off the hair 

 from caterpillars about to moult, without in the least 

 affecting the hairs on the new skin; but when a foot 

 or any other member is accidentally multilated, it is 

 also wanting in the moulted caterpillar, facts which 

 strongly corroborate the details we have given above. 



It is a still more singular circumstance, ascertained 

 by Swammerdam, De Geer, Lyonnet, and Bonnet, that 

 caterpillars and grubs not only cast their external skins, 

 but also that which lines their breathing-tubes and in- 

 testines, ' Some days,' says Bonnet, ^ before the 

 change, the caterpillar voids along with its excrements 

 the membrane which invests the interior of its stomach 

 and intestines. I have also remarked, that during the 

 moult, packets of the tracheal vessels may be seen 

 attached to the cast skin, and thrown off along with it.' 

 De Geer has distinctly seen white fibres proceeding 

 from the interior spiracles of a butterfly remain at- 

 tached to the pupa-case. He conjectures that these 

 fibres consist of the delicate membrane which lines the 

 wind-pipes; and that they are moulted like the lining 

 of the stomach of a lobster, or of a caterpillar. Ly- 

 onnet, in some measure, confirms this conjecture.* 



In his admirable description of the rhinoceros-beetle 

 (Onjctes nasicornis), Swammerdam says of the grub: 

 * Nothing in all nature is, in my opinion, a more won- 

 derful sight, than the change of skin in these and other 

 the like grubs. This matter, therefore, deserves the 

 greatest consideration, and is worthy to be called a 

 specimen of Nature's miracles. For it is not the ex- 



* Bonnet, QEuvres, vol. viii, pp. 303-311. 



