The Hairs of Caier pillars. 167 



even the most careful liaudling of the brown tail has caused pain, 

 and the person so affected, incautiously like Keamur, rubbing the 

 face, could scarcely see out of his eyes for days after. When the 

 hairs of this caterpillar are examined under the microscope the 

 •wonder ceases, as it -will be seen they are admirably adapted to 

 penetrate, whichever end touches the skin, while the jagged portion, 

 barbed like an arrow, remains firmly fixed in the wound. 



The typical form of hair among caterpillars is cylindrical and 

 terminating in a sharp point ; the hair itself being composed of 

 the same chitonous substance as the skin of the animal, generally 

 hollow and fined with a substance, which seems to resemble cutis. 

 Many, if not all, hairs, in the living state, contain fluid matter, 

 possibly of the same nature as the cii'culatory fluid of the animal. 

 Instead of springing from a bulb, as in mammals, the base of the 

 hair is inserted in a socket, a ring-shaped projection, from which 

 the hair easily parts company. Examples of simple hairs of this 

 character may be obtained from the larv^ of the oak eggar and 

 lappet, both of which UTitate some persons. The larvae in each 

 case utilize their hairs in forming their cocoons, as is often pain- 

 fully evident to some, when handling them. A member of my 

 family cannot touch a cocoon of the oak eggar, however old it may 

 be, without annoyance, while I can handle them with impunity. 



In the case of the garden tiger, hop dog, and some others, 

 the hairs are deeply spinous from point to base. In the satin, 

 sycamore tussock, and some others, the spines are thickly studded 

 along the whole hair. In the case of the gipsy, the drinker, and 

 the lackey, all of which, and especially the last named, punish some 

 very severely, the hairs are very fine and beset throughout their 

 length by very minute spines. In the brow^n tail, among longer 

 spinous hairs, are immense numbers of very minute ones jointed 

 throughout their length, and readily separating into barbs sharply 

 pointed at one end and trifid at the other. These hairs part from 

 the caterpillar so readily that persons looking at them, while they 

 were feeding, have felt annoyance, as though the mere movement of 

 the caterpillar separated the hairs, which, hke those of the pro- 

 cessionary moth, were wafted by the wind. Some very peculiar 

 hairs are found on the vapourer, knobbed and plumed at the end ; 

 a similar, but more extensive knob is seen on the hairs of a South 

 American catei-pillar. The hairs on the tortoiseshell and other 

 Vanessidse are very stout and jointed, w^hile those from the white- 

 plume moth caterpillar are imbricated and have somewhat the 

 appearance of wool : sufiicient has been said to show there is so 

 great variety and beauty among caterpillar hairs as to recommend 

 them to the notice of microscopists, who have simply studied, 

 as far as I can gather, those from the larvae of Dermestes and the 

 pencil tail, which are well known as test objects of great beauty. 



N 2 



