SNAILS AND SLUGS 
169 
The creatures are found in all parts of the 
world, even in desert regions and at high 
altitudes up to an elevation of ten thousand 
feet. Some are terrestrial in habits ; others, 
such as the whelks, the periwinkles and limpets, 
dwell in the sea, and others are found in 
fresh waters. They appear to possess great 
tenacity of life, for they can exist without 
partaking of food for a considerable length of 
time. 
The land snails, although habitually undertak¬ 
ing long fasts—those dwelling in cold countries 
burying themselves beneath the ground during 
the winter, and those that live in hot climates 
passing through a torpid state during the 
hottest and driest months of the year—some¬ 
times extend the normal period of abstinence, 
and have been known to live for four or five 
years without food. 
In regard to their external appearance, the 
shells of snails display great diversity of colour¬ 
ing, some being brown, some yellow, and others 
pink or lilac, the ground tints frequently being 
decorated with dark-coloured bands. In the 
case of the wood-snail (Helix nemoralis), the 
variations of its shell are so great that no less 
than eighty-nine different kinds of markings 
have been recorded in British specimens 
alone. 
