SEED. 93 



103. General Remarks xipon Seeds. — The number of seeds in plants is variable ; 

 somo have but one ; some, like the umbelliferous plants, have two ; some have 

 four. The number varies from these to thousands. A stalk of Indian corn is said 

 to have produced, in one season, two thousand seeds ; a sunflower four thousand. 

 A capsule of the poppy has been found to contain eight thousand seeds. It has 

 been calculated that a single thistle-seed will produce, at the first crop, twenty- 

 four thousand, and at the second crop, at this rate, five hundred and seventy-six 

 millions. In the same species of plants the number of seeds is often found to vary ; 

 the apple and many other fruits might be given as examples. 



Seeds, according as thei/ vari/ in size, have been divided into four kinds : large, 

 from the size of a walnut to that of the cocoanut ; middle size, neither larger than a 

 hazle-nut nor smaller than a millet-seed; small, between the size of the seeds of a 

 poppy and a bell-flower ; 'tninutc, like dust or powder, as in the ferns and mosses. 



When a pericarp separates itself from the parent plant, or when the valves open, 

 the fruit has ceased to vegetate ; hke the leaves at the end of autumn, it has lost its 

 vital principle, and becomes subject to the laws which govern inorganized matter. 

 The maturity of the seed marks the close of the hfe of annual plants, and the sus- 

 pension of vegetation in woody and perennial ones. Nature, in favoring by various 

 means the dispersion of these seeds, presents phenomena worthy of our admiration; 

 and these means are as varied as the species of seeds which are spread over the 

 surface of the earth. 



. a. The air, winds, rivers, seas, and animals, transport seeds, and disperse them in 

 every direction. Those which are provided with feathery crowns, or egrets, as the 

 dandehon and thistle, or with wings, as the rftiple and ash, are raised into the air, and 

 even carried across the seas. Linn£eus asserted that the ERiGEaox catiadense was 

 introduced into Europe from America, by seeds wafted across the Atlantic Ocean. 

 " The seeds," says he, " embark upon the rivers which descend from the highest 

 mountains of Lapland, and arrive at the middle of the plains, and the coasts of the 

 seas. The ocean throws, even upon the coasts of Norway, tlie nuts of the maliog- 

 any and the fruit of the cocoanut-tree, which have been borne on its waves from the 

 far-distant tropical regions ; and this wonderful voyage is performed without in- 

 jury to the vital energy of the seeds." Some fruits, endowed with 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. The pericarp of the Impatiens* upon 

 being touched, when the seeds are ripe, suddenly folds itself in a spiral form, and, 

 by means of its elastic property, throws out its seeds. Animals perform their part 

 in this economy of nature. Squirrels carry nuts into holes in the earth. The In- 

 dians had a tradition, that these animals planted all the timber of the country. 

 Animals contribute also 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 sufficient to prevent the dispersion of plants, climatB 

 forms an eternal barrier which they cannot pass. It is probable, that in future 

 times the greater part of vegetable tribes which grow between the savie parallels 

 of latitude, may be common to the countries lying between them ; this may be the 

 result of the industry 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 within the polar circles the vegetables of the tropics, or those 

 of the poles at the equator ; nature is here stronger than art. That much may be 

 done to promote the growth of tropical plants in our climate is true, but how dif- 

 ferent are they with us, from the same species in their own genial climate! In 

 New England the gardener may toil and watch for years to nurture an orange or 

 lemon tree, which, after all, is stinted in its growth ; while in its own native home, 

 the same plant would have grown spontaneously, in luxuriant beauty. 



h. The diffusion of seeds completes the circle of vegetation, and closes the scene of 

 vegetable life. The shrubs and trees are despoiled of their foliage, the withered 



• The cultivated Impatiens is sometimes called Ladies' -slipper, sometimes Balsamine. 



103. Number of the seeds variable— Size variable — Separation of the pericarp from the plant— What 

 is denoted by the maturity of the seed 1— ff . Dispersion of seeds, how effected ?— Elasticity of some 

 frnits — A^'eiiey of animals— Effect of climate upon the dispersion of plants— &. Circle of vegetation 

 completed. 



