ON GASTEROPODA. S27 
in our orchards and fields. ‘These animals principally seek 
out for their food the young shoots of esculent plants. They 
attack without distinction, like the snails, fruits, the young 
buds of trees, and vegetables of all kinds, when they are 
young and tender. They constitute a real scourge ; for when 
circumstances are favourable to them, 7. e. when the soil is 
rich and humid, planted with herbs of which they are fond, 
and exempt from the visits of animals which devour them, 
they multiply to excess. They have been known completely 
to devastate in asingle night a very large seed plat, the plants 
of which had just begun to shoot forth. This evil is always 
to be apprehended in gardens infested by these animals. ‘To 
prevent its happening, it is necessary to cover the earth, 
or the edges of the plants, with ashes, slacked lime, or 
simply with fine sand. These substances act mechanically 
upon the animal, and hinder it from walking, by attach- 
ing themselves to its body. But care must be taken to keep 
them constantly in a pulverized state. 
Various methods have been devised to destroy these 
noxious animals, but we shall not describe them here; suffice 
it to say, that to prevent them from coming to any circum- 
scribed spot, it is sufficient, as we have said before, to sur- 
round it with sand or dust, or some very agglutinating sub- 
stances which they cannot pass. 
The limaces appear to be found in all the northern zone of 
both continents, as well as in the temperate zone. Accord- 
ingly we find them in Norway, Sweden, Lapland, in all 
Russia, Denmark, and Britain, in all parts of Germany, in 
Greece, in Italy, in France, and in all the southern parts of 
the Mediterranean on the African coasts ; whether they are to 
be found in the rest of Africa is doubtful. It appears certain 
that true limaces exist in North America; at least such is 
the assertion of M. Raffinesque. It does not seem so likely 
that the limaciform terrestrial mollusca, that are found on the 
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