530 SUPPLEMENT 



in his chamber. This insect is almost invisible to the naked 

 eye ; its colour is a dirty white, bordering a little on the 

 brown, with two brown spots produced by the internal parts, 

 which appear through the skin, which is transparent. The 

 body is bristling with hairs, thick, oval, a little narrowed in the 

 middle ; its anterior part is terminated in a cone, or a sort of 

 muzzle, containing the organs of manducation ; the mandi- 

 bles have been distinguished ; the palpi are very short and 

 setaceous ; the skin is smooth and tense ; the eight feet are 

 rather long, always curved towards the plane of position, ter- 

 minated by an oval piece, transparent, and swelled like a 

 small bladder with a long neck, having in front a sort of small 

 cleft or separation. The insect can impart to it all kinds of 

 inflexions, swell and contract it. It dilates it when walking, 

 and contracts it, so as to make it disappear, when the foot 

 does not touch the plane of position, and is raised. The vesi- 

 cle can be folded in two in its length, by reason of the cleft 

 which we have just mentioned. Each moiety is furnished 

 with a small hook, which enables the mite to fix itself on the 

 object upon which it walks. The feet are of equal length, but 

 the two anterior pair are much thicker than the two last. 



The females are larger than the males, and have at the 

 hinder part a small cylindrical tube, perhaps an oviduct, and 

 a small eminence underneath. 



The numerous hairs with which the body is bristled are 

 barbed on both sides, and what is singular is, that the insect 

 can move them on one side and the other. Each hair, says 

 Degeer, must necessarily be attached to, or have communica- 

 tion with, a muscle, which gives it motion. What marvellous 

 mechanism in so small an object ! These sorts of prickles are 

 placed upon the body in regular order : two are observed on 

 the upper part of its anterior extremity, which represent, as it 

 were, two small antennae. There are some on the feet which 

 are finer, and on which Degeer has observed no barbs. 



10 



