114 



THE AMERICAN ENTOMOLOGIST. 



Walker, of the British Museum, iufonns us that 

 an excrescence of very similar form, but black 

 iu color, occurs on the leaves of the Lime tree 

 (2'ilia) in England; but that the character of 

 the gall-maker has not yet been tletermiucd. A 

 French naturalist has, however, detected mites 

 in them, and we have little doubt but the galls 

 are caused by these mites, for mite-galls of 

 somewhat similar form, are common in many 

 parts of this country on llie Plum and Cherry, 

 and we shall take occasion, ere long to describe 

 and figure them. 



THE PARASITES OF THE UUJIAN ANIMAL. 

 The Itch Mite. 



(Acarus acahiei, Liuii ) 

 [ In the til'th iiumber of our First Volume, we 

 gave, under the above caption, an account of 

 the eight true insects that are parasitic on man, 

 and briefly referred to some other ringed ani- 

 mals, not classed with the true insects, which 

 also prey upon him. Among those last is the 

 common Itch Mite, a micro.scopic creature 

 which causes that cutaneous disease — the com- 

 mon Itch. We find such an interesting account 

 of this parasite, by B. Joy Jeti'ries, A. M., 

 M. D., of Boston, iu the January number of 

 Good Health, that we transmit the article to 

 our columns. — Ed.] 



[Fig. 77.] 



Color— ■\\niitisli. 



Our chai>ter is headed by a niagnilicd draw- 

 ing of the little animal we are to describe. 

 It is about one-sixtieth to one-seventieth of an 

 inch in length, just visible to tlie naked eye. By 

 living in the skin of man it produces the disease 

 known as itch. To understand how to treat 

 this troublesome atlection intelligibly, we must 

 first study the natural history of the animal, its 

 habits and habitats. Before doing this, how- 

 ever, it will be interesting and instructive to 

 glauce at the general history of this little crea- 



ture, called in English the Jtch-mUe, and in 

 Latin, Sarcoptes /lomini.t, or Acants scabiei. 

 There is strong evidence in support of the 

 idea that some of the diseases spoken of in the 

 Bible as prevalent among the Jews were, in re- 

 ality, due to the ravages of the Itch-mite iu the 

 skin. Probably, when mankind began to peo- 

 ple the world, these insects began to people 

 them, derived, by contagion, from the lower 

 animals previously in existence. From a pass- 

 age in Aristotle's " History of Animals," it has 

 been supposed that the insect was known to 

 him as the cause of the itch. The old Arabian 

 pliysicians, in their Writings, mention it ijuilc 

 plainly — Avenzoar, for instance; but apparently 

 we must come down to the twelfth century 

 for indisputable reference to the Itch-mite, in a 

 work entitled '' Physica,'' written, curiously 

 enough, hy Saint Hildegard, the Lady Superior 

 of the Convent on the Kuperts-Berg, near Biu- 

 gcn. From that time downwards, the insect 

 has been seen and spoken of by the medical 

 writers of the times, as Guy de Chauliac, Gra- 

 lap, Benedictus, Paracelsus, Ambrose Pare, 

 Scaliger, Fallopius, Joubertns, Vidius, Schenck, 

 Haflenrefler, Riolauus, Mouffet, and many oth- 

 ers. These names carry us down to th.e early 

 part of the seventeenth century, to Jansen's 

 discovery of the microscope, in 1C19. The 

 knowledge of the use of the then primitive in- 

 strument soon spread, and the Itch-mite was 

 studied by it, the first rough drawings of the 

 animal being given by Hauptmann. During 

 this (the seventeenth) century, the various wri- 

 ters on medical topics show more or less know- 

 ledge of this mite. We will not, however, tire 

 our readers by quoting their names. Some of 

 them mention the custom, which has been a 

 common practice from that day to this, of ex- 

 tracting the Itch-mite from the skin hy mean.s 

 of a needle. Although, by this time, the mite 

 had been depicted, and its association with the 

 Itch disease recognized, yet it was not till 1687 

 that Dr. Bonomo, of Leghorn, and Cestoni, an 

 apothecary, studied our little friend in what we 

 should now call a common-sense way, and thor- 

 oughly exploded the old ideas, handed down 

 from one generation to another, that the Itch 

 disease was due to thickened bile, drying of the 

 blood, irritating salts, melancholic juices, and 

 special fermentation— the presence of the Itch- 

 mite, when admitted, being accounted for by 

 equivocal generation. These observers saw 

 and described the insects quite perfectly, tbund 

 their eggs, and discovered the females laying 

 them, and came to the conclusion that the Itch 

 disease or scabies arose solely from the presence 



