842 On the Physiology of Vegetables. 
conclusion, this nutriment is so bestowed as to be yielded to it in 
so visible and evident a manner, as always (if the vegetable be 
laid open) to be apparent to the eye, and clearly and easily un- 
derstood by the mind, by the help ofasmall half-guinea mag- 
nifier:—whether it is the bud, the fower, or the seed, they are ald 
nourished nearly in the same manner, but at different limes; 
and the whole process to be traced by the eve, and when it is 
the nourishment of the earth, to be followed from the root up- 
wards—if the dissector will take the trouble to investigate it: 
but in the seed-vessel it is peculiady so. Ihave shown how the 
little heart of the seed is formed in the radicle, and carried from 
the root up the alburnum in the stem, and from thence to the 
seed-vessel at the bottom of the bud. (See fig. 1, Plate V.) T 
shail now explain in how curious a manner part of the seed is 
filled up by the atmosphere, and afterwards by the earth.—This 
is exemplified in no plants in a better or plainer manner than 
in the wheat and gourd. The nutriment is first bestowed by the 
atmosphere: the mechanism is then so wonderful and so beau- 
tiful, that the dullest being would be struck with admiration and 
astonishment, if viewing the graceful feather that performs the 
operation. (See fig. 2. Plate V.) After fructifying the plant and 
partly filling the heart, the juices of the atmosphere hill up the 
bag of the seed move than one-third, before the vessels that run 
up from the reot epen their mouths to bestow their quota of 
nourishment. which is collecting in the pth for the purpose: 
—But all this the print will best explain. 
As soon as the males or stamens appear hanging out of the 
scales, the wheat must be taken: it will then be found that the 
heari of the seed (fig. 2. a, a), has just entered the bag of the 
seed, which is then (except the corculum) empty, or inflated 
with air only. As soon as the heart (aa) is fastened at the top 
of the bag, all the beautiful mechanism appears from which the 
nutriment of the atmosphere will arise: at that time the pollen’ 
spreads all over the featiier of the stigma, dissolves when mixed 
with the sweet juice it there encounters, and runs down the feather 
for the impreguation of the seed :—it may be seen at fig. 4, of 
what regular pitchers the feather is composed, for its reception. 
As soon as the impregnaticn of the heart of the seed is com- 
pleted, then the feather cleanses itself from the pollen, and the 
pitchers which had before beenso filled with the sweet juices of the 
line of life, as not to admit the moisture continually falling from 
the heavens all around it; but the sweet juice now disappearing, 
and the pitchers being empty, open again to receive the juices 
of the atmosphere, and the bag of the seed begins visibly to fill. 
But it is not the feather alone which conveys nourishment from 
the atmosphere; the quantity of hairs which surround the grain 
of 
