342 M. W. B. Thomas on Indications of Weather 
yellow, and, lastly, to a dark brown. The helix is very 
careful not to exude more of its moisture than is necessary. 
It might exude it all at once, but this is not in conformity 
to its general character, as this would prove too great an 
exertion. The Helix alternata is never seen abroad, except 
before a rain, when we find it ascending the bark of trees, 
and getting on the leaves. The Helices arborea, indentata, 
ruderati, and minuta, are also seen ascending the stems of 
plants two days before a rain. The Helices clausa, ligera, 
Pennsylvanica, and elevata, generally begin to crawl about 
two days before rain will descend. They are seen ascending 
the stems of plants. If it be a long and hard rain, they get 
on the sheltered side of the leaf; but, if it be a short one, 
they get on the outside of the leaf. The luccinea have also 
the same habits, differing only in colour of animals, as, before 
the rain, it is of a yellow colour, while after it is blue. The 
Helices solitaria, zaleta, albolabris, and thyroideus, not only 
show signs by means of exuding fluids, but by means of pores 
and protuberances. Before a rain, the bodies of zaleta and 
H. thyroideus have large tubercles rising from them. 
These tubercles commence showing themselves ten days 
previous to the fall of rain they indicate ; at the end of each 
of these tubercles is a pore. At the time of the fall of the 
rain, these tubercles, with their pores opened, are stretched 
to their utmost, to receive the water. Also, for a few days 
before a rain, a large and deep indentation appears in the 
HH. thyroideus, beginning on the head, between the horns, 
and ending with the jointure at the shell. The Helices so- 
litaria and zaleta, a few days before a rain, crawl to the 
most exposed hill side, where, if they arrive before the rain 
descends, they seek some crevice in the rocks, and then close 
the aperture of the shell with glutinous substance, which, 
when the rain approaches, they dissolve, and are then seen 
crawling about. In the Helix albolabris, the tubercles 
begin to rise after a rain, while before, they grew smaller, 
and, at the time of the rain, the body of the snail is filled 
. with cavities to receive the moisture. The H. zaleta, thy- 
roideus, and albolabris, move along at the rate of a mile in 
forty-four hours. They inhabit the most dense forests, and 
