226 
found to contain 1000, and one of the White Poppy 3000 seeds. Each cap¬ 
sule of the Vanilla contains from 10,000 to 15,000 seeds! 
Ray informs us, from actual experiment made by himself, that 1012 
tobacco-seeds are equal in weight to one grain; and that the weight of the 
whole quantity of seed in a single stalk of tobacco , is such, that the number 
of seeds, according to the above-mentioned proportion, must be 300,000! 
The same learned naturalist justly computes that the annual produce of 
a single stalk of the Spleen-wort (Asplenium) to be upwards of one million 
of seeds! 
Du Hamel relates that a single grain of barley produced in 1/20, 154 
spikes, which together contained 3300 grains, which being sown the follow¬ 
ing year, produced rather more than a bushel; and this being sown, pro¬ 
duced in 1/22, 45 other bushels and a quarter. In another instance a single 
grain of barley produced 200 spikes, and these contained 4800 grains, and 
the next year these last would have produced 23,040,000; and the product 
of the third year would have been 110,502,000,000; and the fourth year 
beyond the bounds of calculation. 
Dr. Woodward has calculated that a single thistle-seed will produce at 
the first crop 24,000 seeds; and consequently, jive hundred and seventy-six 
millions of seeds at the second crop! 
Well then might Yirgil sing, 
Mox et frumentis labor additus: ut mala culmos 
Esset rubigo; segnisque horreret in arvis 
Carduus; intereunt segetes; subit aspera sylva, 
Lappaeque, tribulique Georg. Lib. L 
In order to secure the existence of plants, nature hath contrived various 
modes of dispersing abroad the seeds, which, as they find a soil adapted for 
their state, either take root and establish themselves, or perish, to become 
manure for other vegetables. 
The modes of dissemination are extremely various, as, 
I. By a peculiar elastic spring in the pericarp , or seed-vessel. 
II. The appendages attached to seeds. 
III. From seas 7 rivers , and brooks. 
IY. Birds , and other animals. 
% 
1. Many seeds are dispersed to a considerable distance by means of an 
elastic force which resides in some part of the fructification. This is very 
