10 : THE LAND SNAILS 
the course of two or three weeks, furnished with a shell 
composed of one whorl and a half. The shell is increased 
in size by the addition of calcareous matter round the 
margin of the aperture. The successive lines of growth 
can be easily traced on the shells of most species. They 
attain their complete growth in from one, to two years. 
The number of eggs produced by an individual varies in 
proportion to the greater or less protection afforded to the 
animal ; thus in the common slug, Limax, and allied gen- 
` era, having no exterior shell into which they may with- 
draw in times of danger, the number of eggs produced is 
much greater, and according to Dr. Peeks; hiv kept two 
specimens of the common garden slug in confinement, 
seven hundred and eighty six eggs were laid in one year. 
The vitality which the snails eggs possess surpasses be- 
lief. Certain French fhiduradiaty assert that they have 
been so completely dried, as to be friable between the 
fingers. In this dried condition they have been kept fora 
long time, and yet a single hour’s exposure to humidity and 
warmth, has been sufficient to restore them to their origi- 
nal form and elasticity. They have been dried in a fur- 
nace eight successive times, until they were reduced to an 
almost invisible minuteness, yet in every interval have 
they regained their original bulk in a moist situation. In 
all thèse instances the young have been developed, in the 
same manner as other eggs not subjected to this ex- 
periment. (Binney.) This wonderful vitality extends to 
the snail in all stages of its existance. We have seen cer- 
tain species frozen in solid blocks of ice, and yet regain 
their activity when subjected to the influences of warmth. 
Their dependence on moisture naturally places them in 
moist situations, yet we have seen certain species attached 
to leaves, where the sun had shed its scorching rays for 
si tag cl 
ipa, 
ie al 
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