HARDWICKE'S SCIENCE-GOSSIP. 



107 



By what instinct they are led to arrange them- 

 selves in this singular manner it is impossible to 

 say ; but so compact is the body, and so well-set 

 the ranks, that the spectator rarely, if ever, sees a 

 head protruding beyond its neighbour next in ad- 

 vance; the line, in fact, is as firm and well-arranged 

 as in the best regiment of a well-disciplined army. 

 Nor is this all : no sooner does the leader stop, than 

 the ranks immediately behind him come to a halt, 

 as though by a common impulse, and a fresh move 

 forward is made with the same precision and regu- 

 larity. This contimies until the new'feeding-ground 

 is reached, when the caterpillars disperse for a 

 while, ready to rearrange themselves at some signal 

 entirely hidden from our ken. 



So far these little creatures appear as very harm- 

 less members of insectdom ; but however much we 

 may admire and wonder at the strange instinct 

 which guides these larvae on their path, it is well 

 not to venture too near their forest haunts, for they 

 are gifted with a property which renders them any- 

 thing but pleasant neighbours. I allude to the 

 " urticating " nature of the hairs with which the 

 caterpillars are clothed. 



The moths themselves are perfectly innocent ; 

 sombre in colour and quiet in their habits, they live 

 the usual insouciante existence of their tribe, never, 

 willingly obtruding themselves on the world : it is 

 the progeny to which they give birth that makes 

 itself felt, in more senses than one. No sooner are 

 the little torments brought into the world, than they 

 surround themselves with a common web, within 

 which they seek shelter, and to which they retire 

 when danger threatens. 



All this is only what is done by our Ermines and 

 Gold-tails, and many others of our native Lepido- 

 pters; but unfortunately for the good name of these 

 Cnethocampids, and for the peace of mind of those 

 who come near them, these caterpillars are clothed 

 with tufts of hair of a peculiar and most aggravating 

 kind. The web, too, which grows with their growth 

 until it is sometimes as large as a man's head, be- 

 comes impregnated with these hairs, which are very 

 long, of a black and white colour, and either smooth 

 or barbed and feathered (fig. 63). 



Woe to the person who incautiously meddles 

 with one of the nests, or picks up a caterpillar. No 

 sooner do these poisonous hairs come in contact 

 with the surface of the body, than they produce an 

 itching sensation, followed by inflammation more or 

 less severe, according to the state of the victim 

 and the condition of the atmosphere. Sometimes 

 the effects are no worse than those made by the 

 sting of a nettle, the wounded part swelling, and the 

 skin after a while peeling off : at others, the irrita- 

 tion caused by the entrance of the pointed hairs 

 into the pores of the skin has been known to pro- 

 duce a very serious illness, and even death. 



From their very fragile nature, these hairs are 



unfortunately scattered like so much fine dust, and 

 as they cling to whatever damp objects— such, for 

 instance, as the human body — they may chance to 

 touch, the discomfort, to say the least of it, pro- 

 duced among persons compelled to frequent the 

 forests in which these animals abound, is almost 

 indescribable. To disturb their web-made castles, 

 which are placed against the tree-trunks, or sus- 

 pended from the boughs at a few feet from the 

 ground, is attended with considerable risk, as the 

 hairs are in that case set free and dispersed in every 

 direction. 



Fig. 63. Hairs of the Processionary Moth, magnified. 



The Processionary Moth abounded in the woods 

 which, previously to the late unhappy war, skirted 

 the city of Paris, and were a source of no small 

 annoyance to the citizens, who loved to stroll and 

 picnic in the leafy glades. If there was one spot 

 on earth dearer than another to the Parisian, it was 

 the Bois de Boulogne, as it stretched away from 

 the Arc de l'Etoile, with its pretty rides and alleys. 

 But much of his admiration for his favourite lounge 

 was damped by the presence of the " chenille veni- 

 neuse," as it was termed. Indeed, when their 

 webs were more than usually abundant, as was the 

 case in the year 1865, many parts of the wood were 

 positively closed by the authorities against the pro- 

 menaders. 



In the southern departments of Erance the 

 danger of coming in contact with these treacherous 

 insects is so much considered, that persons com- 

 pelled by business to be near a tree infested by 

 them are recommended to envelop their bodies in 

 oiled linen before attempting to cut off and burn a 

 branch on which a web has been formed. No cattle 

 can be driven into the woods infested by the moth. 

 Woodcutters are warned to be careful to protect 

 themselves by anointing the exposed parts of their 

 bodies with oil : nor should they ever, if possible, 

 approach any part of the forest where the moths 

 abound, in the face of the wind, lest the minute 

 particles of hair be blown into their faces. 



The dead caterpillar is to be as carefully avoided 

 as the living animal. The celebrated Reaumur, in 

 his monograph of this insect (Mem., torn, ii.), men- 

 tions, that while engaged in dissecting it, his skin 



