SPINNING MITES. m 



CASE late Dr. Johnston of Berwick also mentions (Acarides of Berwick- 

 shire, in "History of Berwickshire Naturalists' Club," p. 221) that 

 in Berwickshire this mite was very troublesome to horses, cattle, 

 sheep, dogs, and rabbits, and to the " herds' bairns," and people 

 engaged about the infested animals in that county. It adhered to 

 the skin, and in numbers occasionally so great as to be collected 

 into small clusters, hanging like a drop of congealed blood from 

 the hairs. They produced extreme itchiness ; and his correspon- 

 dent says, *• in the worst case I have seen, that of a horse, the 

 skin seemed exactly as if it had been rubbed with a liquid blister." 

 Hence he inferred that the mite had penetrated beneath the skin, 

 as it is known that it easily does into that of man. When 

 examining it, some individuals got upon his hands, over which 

 they dispersed themselves with considerable quickness, and in a 

 few seconds they had burrowed in the skin so deep as not to be 

 perceived, but the place in which they had burrowed was indicated 

 by itchiness, and by a blister that exactly resembled the pustule 

 occasioned by the sting of a nettle. One individual was watched. 

 Its race over the hand and the moment of its fixation was unfelt ; 

 neither was any uneasiness felt by its penetration of the skin. On 

 getting under the cuticle it was killed by a strong squeeze. No 

 itchiness ensued, nor blister, and the dead insect remained after 

 an interval of more than three months unaltered, the red speck 

 then still marking the spot of its death and burial. Latreille com- 

 pared the symptoms to those of the itch. M. Greeby calls the 

 affection the autumnal erythema ; M. John has observed an exan- 

 thema due to this cause ; and M. Moses cites a case of vesicular 

 and papillar inflammation, with unsupportable itching produced in a 

 family by this insect. Perhaps its effects are more severe in France, 

 where these cases occurred, than in this country. M. Megnin says 

 that the insects are got rid of by means of sulphur ointment, by 

 friction with benzine and oil of petroleum or phenic acid, which 

 we may say in passing are also common remedies for the itch. 

 And here we may put the question. What do these little creatures 



