INSECTS. 193 



chiefly found on meadow sheep ; but relatively few in 

 winter. The parasites leave the body of their host for 

 the purpose of reproduction, and lay their maggots, 

 which at the time of birth are nearly one-sixth of an 

 inch long, under little bits of earth or heaps of dung. 

 When sheep are kept in folds no permanent result 

 can consequently be expected from the use of any 

 remedy if, at the same time, the fold and all its con- 

 tents are not kept clean. The walls must be cleansed, 

 and washed with caustic potash, to which carbolic 

 acid has been added. Curative Washes: A decoction 

 of walnut leaves and vinegar. Turpentine, soapsuds, 

 decoction of tobacco. Washes containing arsenious acid 

 (e.g. Bigg's Improved Sheep and Lamb Dipping Com- 

 position) must be used with caution ; unpalatable sub- 

 stances may be added, so that the sheep will not lick 

 them, or else a muzzle may be employed. 



Ninth Okder: Aphaniptera (Fleas). 



Body strongly compressed laterally. Head small. 

 Mouth-parts adapted for sucking and biting. Legs 

 long, especially the last pair. They possess the power 

 of springing. Wingless. Complete metamorphosis. 

 Larva worm-like, legless, hard-headed. The Dog Flea 

 (Fulex serraticeps), which only occasionally passes 

 on to human beings, lives on dogs and cats. Memedy : 

 Sprinkling the moistened hair with Persian insect 

 powder or powdered parsley seed. 



Tenth Order : Parasita (Lice). 



Body flattened. Legs adapted for climbing among 

 hairs and feathers, as the last joint of the foot is hook- 

 shaped, and can be bent back against the preceding 

 joint ; a hair can thus be held fast between the two 

 joints. Eyes absent or ill-developed (simple). Wing- 

 less. The eggs (" nits ") are fastened by the mother 

 louse to the hairs of the host ; the young lice resemble 



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