442 
WORMS. 
Leeches are found in marshes and ponds with a bottom of mud or clay, and 
overgrown with weeds. They cannot live long out of water and die as soon as 
the skin dries, though for some 
time they may protect them¬ 
selves from this by the 
excretion of slimy matter. 
By day, and especially in 
warm weather, they swim 
about with liveliness, but at 
night and in dark, foggy 
weather, or on cold days they 
remain quiet and curled up, 
and in the autumn they 
bury themselves deep in the 
mud. They feed largely 
upon the blood of fishes, 
frogs, or mammals, but some¬ 
times, in cases of necessity, 
devour each other. After 
COMMON LEECH. . . , , . ,1 
pairing m the spring, the 
A, From above (nat. size); B, From the side, swimming (mat. size); . . . . . , 
C, Head cut open to show mouth (enlarged); I), Egg-cocoon (enlarged.) SUCtlOnai leeches DOie into the 
soft spongy ground just above 
the level of the water, and at the end of July or thereabouts begin to form their 
cocoons or egg-cases, one of which is shown at D in the above illustration. These 
cocoons are formed of a greenish mucus, or slimy material, and in them from ten 
to sixteen eggs are laid. The mother then closes the aperture, and over the whole 
2 
STRUCTURE OF LEECH. 
1, Alimentary canal— a, CEsophagus ; b, Saccular stomach ; c, Last pair of pouches. 
2, Anterior end, showing eyes. 3, Jaw. 
pours out a whitish saliva-like froth, which upon drying forms a spongy coating 
to the case. The cocoons are placed in the burrows, and from four to six weeks 
after the laying, the young creep forth. These are thread-like and clear, but like 
the old ones in form; and appear to attain their full size in about five years, 
although they may live as many as twenty. 
The colour of the medicinal leech is black above, generally ornamented with 
pale bands. This species extends over the greater part of Europe, and has been 
found in France, Germany, England, Russia, and Sweden. Another nearly allied 
