241 
stop short and leave the reader in the dark, precisely where he needs light 
the most. A seed is laid in earth: by what mechanical power is vegetation 
produced and continued during the life of the plant? And by what mecha¬ 
nical power does motion commence in the foetus of an animal, and the 
blood circulate? When a seed happens to be inverted in the ground, with 
its radicle above, and its plume below, what is the mechanical power that 
makes them wreathe about the seed till the radicle gets into earth and the 
plume into air?* Unless these particulars can be accounted for mecha¬ 
nically, an embryo must be held a pure vision. A power must be admitted 
even in the smallest embryo, to expand itself into a plant or animal, where 
it happens upon a proper nidus. And yet the admission of that power 
destroys the hypothesis, root and branch. A seed thrown into the ground 
would rest there for ever, were it not endued with a power to begin vege¬ 
tation, and to continue it. It grows into a tree: why may not that tree be 
endued with a power to form its own seed? If so, there is no necessity to 
go further back: organized atoms or embryos must vanish, because there is 
no use for them. Power in a tree to form its seeds, is no more extraor¬ 
dinary than that of sucking juices from the earth, and converting them into 
its own substance, a power that every plant is admitted to have. 
This subject has been long ago debated, and you may see in the life of 
Malpighi, a dispute betwixt him and Signor Triumphetti, the provost 
of the garden at Borne, whether the whole plant be actually contained in 
the seed. 
Malpighi maintains, “ all organized bodies pass through successive 
changes. Plants, of course, are not exempted from mutation. What an 
amazing difference between an acorn and a stately oak! The seeds of plants 
may be compared to the chrysalis of butterflies. The seed, like the chry¬ 
salis, contains, in miniature, all the parts of the future plant. These parts 
require only time, and other circumstances necessary to vegetation, for their 
complete evolution. How different are the seed-leaves from those of the 
plume! Beside the general changes arising from growth, plants undergo a 
number of metamorphoses from other causes. In northern climates, if we 
* To ascend and descend is not the ultimate view in these two parts, but to get into the air and 
earth. As seeds are generally deposited on or near the surface of the ground, the plume ascends, 
and the radicle descends. But place a seed in an inverted flower-pot with earth in it, the radicle 
ascends, and the plume descends i the first pursues its road into the earth, and the othei into the air. 
3 P 
