THE AMERICAN ENTOMOLOGIST. 



115 



of au animal which is incessantly bitinj;' the 

 skin, and thereby cansing the patient to allay 

 (he itching by scratching. They alsoexphiincd 

 (he contagions cliaracter of the affection by (he 

 transference of the insec(s from one individual 

 to another. Because (hcsn discoveries were 

 (rue, they were denied and combated by (lie 

 medical wrifcrs of those days; yet nearly one 

 hnndred and fifty years passed before anyl^t- 

 ter natnral history of the nii(e appeared, mng 

 r4eorgc TI,.'s physician^ Dr. Richard Mead, of 

 London, reported Bnnomo and Cestoui's obser- 

 vations to the Royal Socie(y, and published 

 them in No. 28;'. of the "Philosophical Trans- 

 iictions."' 



We have given this litde historifeal sketch to 

 show how old the disease is, and how old a 

 knowledge of its cause is also. Notwithstand- 

 ing, from that (irae to (his (1S69) there has not 

 failed to exist medical men or naturalists who 

 deny the coniiecdon bc(\t^ell (he disease called 

 Itch and the Itch-mite. Jt is with medicine as 

 with everything else iijyBio world — denial of 

 truth excites notoriety, sirdesired by the many. 



in view of what we have above said, it seems 

 impossible (o conceive that a correct knowledge 

 of the Itch-mite should be, since Bonomo's 

 time, repeatedly lost in some of the great cen- 

 tres of medical teaching, (o be agaia regained. 

 In 1812, a prize was oft'ered in Paris for the dis- 

 covery of the little insect; and a certain apothe- 

 cary named Gales took it, by exhibiting before 

 a medical commission the Cheese-mite. Conse- 

 <|uently those who searched patients with Itch 

 did not find this animal, and a prize was once 

 moreoftered; and Raspail showed the Cheese- 

 mite again, and, when the judges were satisfied, 

 proved it was such, and exposed Gales' dupli- 

 city. The cause of the Itch-mite had hencefor- 

 ward its adherents and opposers; whilst, in 

 various parts of the world, the lowest classes 

 understood it, and (he methods of its des(ruc- 

 (ion: for ins(ance, (he old women in f!orsica, 

 Avlo picked them out wi(h needles. Kenucci, 

 a native of the Island, probably familiar with 

 these old ladies' occupation, finally, in lH;li, 

 taught the Parisian medical world how to tind 

 the Itch-mite; and, from that time to this, the 

 insect and if* ravages have been more thor- 

 oughly and scientifically studied, and the liter- 

 ature of the subject grown up into quite a der- 

 matological library. In 18+0, Dr. C. Eichstedt, 

 of Griefswald, and Prof. Kriunoi' of Kiel, inde- 

 pendently discovered the male mite. We who 

 now-a-days, Lave treated (he Kch disease, and 

 the natural history of the Itch-mile, naturally 

 feel as if \ve knew pretty much all about it; yet 



so late as 1844, Prof. Ilebra, of Vienna, gave 

 the German pliysicians a knowledge or a new 

 and terrible phase of this insect's habits and 

 habitats, in what is known as the Norwegian 

 Scabies, the first recorded (^a^e having occurred 

 in that country. A:id so it probably will always 

 be ill the ever-advancing science ot medicine, 

 the present generation smiling at the errors and 

 ignorance of the preceding one. But when a 

 truth, like the one mentioned of Hebra's, is dis- 

 covered, then others are rapidly and constantly 

 being found to confirm i(. 0(her cases were 

 soon reported by observers in Germany. 



We suppose, by this time, our readers want 

 to know a little m )re about (he insect itself, and 

 perhaps have had hardly patience to read down 

 so far (o learn about the strange-looking animal 

 heading our article. At present we include the 

 Itch-mite in (he special class of Acnrina, and if 

 our readers want to know more about the other 

 members of this class, as (he Sugar-mite, the 

 Cheese-mite, etc., we would lefer (hem to an 

 article in the September number of (he Ameri- 

 can Naturalist, by our friend A. S. Packard, 

 Jr., who gives numorous and beautilul illustra- 

 tions, accompanied by pleasantly told descrip- 

 tions. Our article will fill up this chapter for 

 the Ararus scabiei, or Sarcoptes homini, or 

 Itch-mite. The animal is tortoise-shaped. The 

 head distinct from (he (runk, Avith four pair of 

 jaws. Eight legs, four in front and four behind. 

 The larva has but six legs. Beside the legs are 

 long bristles. The male dilTers from the female 

 in appearance, as to the bell-shaped suckers on 

 the ends of the legs, and also isnot so large. This 

 insect has been found, not alone in man, but in 

 the skin of the horse, lion, lama, ape, Neapolitan 

 and Egyptian sheep, and (he ferret. It has been 

 thought, also, that the mites found in many 

 other animals ai-e (he same as man's irritating 

 companion, their growth being favored or re- 

 tarded by their place of development, thus ac- 

 counting for the apparent difTerenees in shape 

 and size. The Itch-mite lives in the skin, in 

 little passages dug by itself, or, sometimes 

 just beneath the epidermis or scarf-skin. 

 These burrows the animal extends into the 

 deeper layers of the epidermis, down to and 

 into (ho (rue skin, or rete mucosiim, as it is 

 called. The Acarus moults three times, not, 

 however, specially changing in form. The eggs 

 are oval in shape, quite large for the size of the 

 animal, and may be laid by (he female to (he 

 number of fifty. We give here three drawings, 

 (o show how the animal gels into (he skin to 

 form (he burrows, now i-alled "acarian fur- 

 rows" bv derniatolo'jfisls. 



