250 MEANS OF DEFENCE OF INSECTS. 



mode it, from each of the above branches there issues a 

 long, cyhndrical, slender, fleshy, and very flexible organ 

 of a rose colour, to which the caterpillar can give every 

 imaginable curve or inflection, causing it sometimes to 

 assume even a spiral form. It enters the tube, or issues 

 from it, in the same manner as the horns of snails or 

 skigs. These tails foi'm a kind of double whip, the tubes 

 representing the handle, and the horns the thong or lash 

 with which the animal drives away the ichneumons and 

 flies that attempt to settle upon it. Touch any part of 

 the body, and immediately one or both the horns will 

 appear and be extended ; and the animal will, as it were, 

 lash the spot where it feels that you incommode it. De 

 Geer, from whom this account is taken, says that this 

 caterpillar will bite very sharply ^. — Several larvte of 

 butterflies, distinguished at theii head by a semicoronet 

 of strong spines, figured by Madame Merian, are armed 

 with singular anal organs '', which may have a similar 

 use. Rbsel when he first saw the caterpillar of the puss- 

 moth, stretched out his hand with great eagerness, so he 

 tells us, to take the prize ; but when in addition to its 

 grim attitude he beheld it dart forth these menacing ca- 

 tapults, apprehending they might be poisonous organs, 

 his courage failed him. At length, without touching the 

 monster, he ventured to cut off" the twig on which it was, 

 and let it drop into a box *= ! The caterpillar of the 

 gold-tail moth [Arctia chrijsorhcea) has a remarkable 

 aperture, whicli it can open and shut, surrounded by a 

 rim on the upper part of each segment. This aperture 

 includes a little cavity, from which it has the power of 



* De Geer, i. :V22— " Ins. Sunufim. t. viii. xxiii, xxxii. 



' I. iv. 122. 



