CH. III.] INSECTS WHICH FORM COCOONS. 55 



the moth on effecting its escape, and causing the 

 whole to look like an assemblage of empty cells. 

 These insects are remarkable for another quahty, 

 which renders it very unpleasant to approach their 

 nests, or to handle the caterpillars. Reaumur had 

 cause to speak very feelingly upon the subject, hav- 

 ing suffered very severely from the intolerable irri- 

 tation produced by their hairs. Reaumur likens 

 these caterpillars to a species of bean which is 

 brought from the American islands, the pods of 

 which are covered with hairs so exceedingly sharp 

 and fine, that, on touching or rubbing them with the 

 hand, they run into the flesh : in like manner the 

 hairs of these caterpillars, on being touched by the 

 hand, cause it to swell : and Reaumur and some of 

 his companions suffered for four or five days from 

 the inflammation produced by them : his face, and 

 especially one of his eyes, being very much affected 

 in consequence of his having touched them with 

 his fingers on which the hairs were sticking. Sev- 

 eral ladies also, who were with Reaumur, but who 

 did not handle the caterpillars, had their necks in- 

 flam.ed, and it was evident that this was produced 

 by the very fine hairs which were floating in the 

 atmosphere. This was especially the case after the 

 insects were transformed into chrysalides and 

 moths, being seldom observed while the insects re- 

 mained in the caterpillar state. However, so pow- 

 erful is their action, that Reaumur suggests that 

 they might advantageously be used as vesicatories ; 

 and, indeed, no less than two enactments were 

 made by the Roman senate against the medicinal 

 exhibition of them, under severe penalties, in con- 

 sequence of their virulence. The only remedy 

 which Reaumur was able to discover to counteract 

 the effects of these hairs, was to rub parsley-lea<^es 

 smartly upon the affected parts for several minutes. 

 This he found so efhcacious, that, in the parts thus 

 : rubbed, the irritation immediately subsided. 



