264 MANUAL OF NATURAL HISTORY. 



from others of their Order by means of their long 

 flattened bodies* They are nocturnal in their 

 habits, shunning the light, and usually conceal- 

 ing themselves under logs of wood, among loose 

 stones, under the bark of decayed trees, or in the 

 timbers of buildings. In hot climates they fre- 

 quently attain to a formidable size, and their bite is 

 then considered dangerous. They chiefly inhabit 

 tropical countries, though a few small and harmless 

 species occur in the southern parts of Europe, and 

 one (Lithobius forcipatus) under damp moss, &c, in 

 England. A few slender species are found to ex- 

 hibit a vivid phosphorescent light. The hollow 

 mandibles of the poisonous species end in a sharp 

 hook, which is perforated at the point for the 

 passage of the venomous fluid. The Juli, another 

 group frequently observed, are at once distin- 

 guished from the Centipedes, by their long, slen- 

 der body not being flat but cylindrical. These are 

 perfectly harmless, and feed upon decaying vege- 

 table matter. They are found in the loose earth, 

 among moss, or under stones. Some of the large 

 Asiatic species attain a length of six or seven inches. 

 When they walk they move with a sort of undulat- 

 ing motion like a serpent, and when alarmed coil 

 themselves up in a spiral form. 



The Spring-tails, including the first part of the 

 Thysanur% are usually found lurking under stones, 

 or in the crevices of the bark of trees. By placing 

 the elastic forked appendage of their tail under 

 the body, and suddenly straightening it, they are 



