WHAT LEECHES ARE FED UPON. 223 



water from a well, nor spring water, as it issues from 

 the earth ; that vessels of earthenware are preferable 

 to vessels of glass or glazed earth ; and that darkness 

 is fatal to leeches. 



But to return to the mode of feeding followed by M. 

 Borne; here it is: Placing the leeches in little bags, 

 he plunges them in a bath of warm blood flowing from 

 the veins of an animal. The bags are of flannel or of 

 fine linen, for large and moderately large leeches. The 

 very small leeches are put in bags of muslin or fine 

 flannel, and carried to the shambles. When the ox, 

 calf, or sheep is bled, the blood is beaten in order to 

 destroy the fibrine, and hinder the formation of clot, and 

 then the bags are plunged in it. The tissue in which 

 the little creatures are shut up serves as a point of at- 

 tachment for sucking and affords the means of occasion- 

 ally looking at them, to see if they are gorged. The 

 larger leeches are left in this bath of warm blood for 

 five or six minutes, those of middle size for about ten 

 minutes, the small ones for a quarter of an hour, and 

 the very small ones for half an hour. They are then 

 taken out, washed in warm water, and then placed in 

 cold water to be taken back to the marsh. 



M. Sauve also uses bags to gorge his leeches, but in 

 some respects his plan differs from that of M. Borne. 

 He carries the blood in cans with double bottoms, which 

 are filled with boiling water to prevent cooling ; and 

 then, like M. Borne, he plunges into the vessels full of 

 blood the leeches in bags of linen, or preferably of 

 woollen. This warm blood, which retains its fibrine, 

 is, M. Sauve maintains, much superior to that which 

 has lost its heat and its fibrine. 



It is a kind of satisfaction to know that these blood- 

 thirsty creatures are preyed upon by many enemies, and 

 make dainty morsels to sand-mice, water-rats, moles, 

 the larvae of the dragon-fly, eels, herons, and, above 

 all, wild-ducks. Well may leech -breeders quake when 

 told that in twenty-four hours 200,000 leeches have 



