SEED. 
121 
period of the life of annual plants, and the suspension of vege- 
tation in woody and perennial plants. Nature, in favouring by 
various means the dispersion of seeds, presents phenomena wor- 
thy of our admiration, and these means are as varied as the spe- 
cies of seeds which are spread upon the surface of the earth. 
The atmosphere, winds, rivers, seas, and animals of all spe- 
cies, transport the seeds and disperse them in every direction. 
Seeds provided with feathery crowns, (egrets,) as the dandelion 
and thistle ; with wings, as the maple and ash, are raised into 
the air and even carried across the seas. Linnaeus asserted that 
the Erigeron canadense was introduced into Europe from 
America, by seeds wafted across the Atlantic Ocean. “ The 
seeds,” says Linnaeus, “ embark upon the rivers which descend 
from the highest mountains of Lapland, and arrive at the mid- 
dle of the plains, and the coasts of the seas. The ocean has 
thrown even upon the coasts of Norway, the nuts of the mahog- 
any, and the fruit of the cocoa nut tree borne on its waves from 
the far distant tropical regions : and this wonderful voyage has 
been performed without injury to the vital energy of the seeds.” 
Some fruits endowed with great elasticity, throw their seeds 
to a considerable distance. In the oat, and in the greater num- 
ber of ferns, this elasticity is in the calyx. In the Impatiens , 
in the cucumber, ( Cucumis ,) and many others, it resides in the 
capsule. The pericarp of the Impatiens, consists of one cell 
| with five divisions ; each of which when the seeds are ripe, upon 
being touched, suddenly folds itself in a spiral form, leaps from 
the stem, and scatters by means of its elastic property, its seeds 
to a great distance. 
Animals also perform their part in the diffusion of seeds. 
Squirrels and other animals carry seeds and nuts into holes in 
the earth. The Indians believe that the squirrels plant all the 
timber of the country ; though this may be au exaggeration, 
there is no doubt but that they do much towards diffusing differ- 
ent kinds of nuts and seeds ; as chesnut, oak, walnut, &c. 
Animals contribute to the distribution of seeds by conveying 
them in their wool, fur, or feathers. Although distance, chains 
of mountains, rivers and even seas, do not present obstacles suf- 
ficient to prevent the dispersion of vegetables, climate fixes an 
eternal barrier which plants cannot pass. It is not unlikely 
that in future times the greater part of vegetable tribes which 
grow between the same parallels of latitude, may be common to 
all countries of that zone ; this may be the result of the indus- 
try of man, aided by the efficient means which nature takes to 
promote the same object in the dissemination of seeds ; but no 
human power can ever cause to grow Avithin the polar circles, 
11 
Dispersion of seeds. 
