SPIDERS, MITES, AND SCORPIONS. 



165 



Fig. 147. — Tarantula, natural size. 



properly belongs to a large, long-legged form living in Italy and Spain. 

 Connected with this species there is a most peculiar superstition which 

 has endured for ages, and 

 which, so far as is known, 

 lias no actual foundation 

 in fact. The story goes 

 that the bite of this spicier 

 produces a peculiar insan- 

 ity known as tarentism, 

 which can only be cured 

 by prolonged dancing to a 

 peculiar style of music. In 

 reality the bite of this 

 maligned monster produces 

 scarcely any effect on some 

 persons ; on others it is fol- 

 lowed by consequences no 

 more serious than the sting 

 of a wasp. 



The most degraded of all the group of spider-like forms are the mites, 

 few of which attain any considerable size. In them there is not that divis- 

 ion of the body into the regions so prominent in the spiders and scorpions, 

 and almost all of them live a parasitic or semi-parasitic life upon other 

 animals or plants. Some, however, live free, and among these are a lot 

 of aquatic forms resembling to a greater or less ex- 

 tent the American species figured in the adjacent cut. 

 This form, however, lives a parasite life upon the gills 

 of the fresh-water mussels. 



Of the other forms, several must be mentioned at 

 least by name. First there comes the itch-mite, which 

 is the cause of the loathsome disease — the itch — now 

 happily almost extinct. This is a very minute form 

 which burrows just beneath the skin of man, produc- 

 ing a most intolerable itching. The connection be- 

 tween the parasite and the disease has long been 

 known, having first been pointed out by an Arabian physician some seven 

 hundred years ago. Closely allied to this is the form which produces the 

 mange in dogs.* Even more degraded than these forms are the so-called 

 follicle-mites which occur in the sebaceous follicles of pigs, cattle, and 

 occasionally in the skin of man. They are elongate, worm-like animals 

 of minute size, which, however, betray their affinities to the mites and 



Fig. 148.— Water-mite 



{Atas ). 



