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structions of light, or to shoot into long and slender 
poles by being closely crowded ; and fruits, as gourds, 
may be artificially made to grow into various conve- 
nient or fantastic forms. Plants may be gradually 
induced to bear changes of climate, to which a 
sudden exposure would be fatal. The arbutus and 
laurustinus from Italy are familiarized to our shrub- 
beries, with roses from Persia and China, and with 
jonquils and asters, with peaches, and nectarines, 
and tulips, and geraniums, in fact, with all the chief 
luxuries and beauties of our gardens. Yet the com- 
panions of the arbutus and laurustinus in Italy, and 
even in the south of France, the ceratonia, or carob, 
and the olive, are not yet domesticated with us. 
I cannot meet with any account of experiments 
on the docility of any of the mollusca, or crustacea, 
unless the spiders be reckoned among the latter. 
My well informed friend Mr. Pratt, who obliging- 
ly arranged the shells in the Ashmolean Museum §, 
tells me, that he knew a French naturalist who had 
contrived to obtain a breed of reversed snails, which 
he sold with advantage to the lovers of rarities. 
When a garden snail is placed with its apex verti- 
cal, its aperture expands ordinarily to the left. 
The line of curvature is swelling toward the right. 
But varieties occur, though rarely. The rarity gives 
them value to collectors. The Frenchman obtained 
a living pair, and produced a fine family, all of whom 
k Some genera of shells are more usually found sinistral than 
otherwise, such as the pupa; others in which some of the species 
are not unfrequently so, as achatina, helix, bulimus. 
