EERE TE TRIE GEE Ta SS Ge en ee 
BEAN. 
- 
a larger quantity of straw, which makes excellent 
manure. But some of the other sorts are gener- 
ally supposed to yield larger products. ‘This, 
however, is a point on which some well-conducted 
comparative experiments are wanting.” 
Bean-seeds retain their vitality very long after 
they become so dry as to be shrivelled and hard ; 
yet when long kept, they do not germinate so 
soon as when comparatively fresh. In judging 
of their age and their other qualities, one or two 
should be so bitten across as to make them crack 
or split in an opposite direction to that of their 
length. A bean which is easily fractured, and 
whose interior exhibits a dry and husky but not 
powdery appearance, is either old or has been 
kiln-dried or heated in the mow. But a bean in 
full possession of its vitality and of its capacities 
for speedy and vigorous germination, can be al- 
most as easily bitten asunder in any other direc- 
tion as down the middle, and cannot without 
difficulty be cracked or fractured, and exhibits a 
toughish and fresh-looking interior. When none 
but oldish beans can be obtained for seed, they 
ought to be sown fifteen or twenty days earlier 
than if they were fresh. 
The Physiology of the Bean—A bean of any of 
the larger varieties affords a remarkably distinct 
and most beautiful exemplification of the phe- 
nomena of germination and nascent vegetable 
growth. The cotyledons or seed-lobes are large 
and fine specimens of phytological albumen [see 
our second article ALBuMEN |], and serve as stores 
or sources of suitable nourishment for the infant 
plant in a manner analogous to the albumen of 
eggs for embryo birds, or to the milk of the ani- 
mal breast for the young of the animal. The 
‘plume, plumule, or germ of the future stem, is 
a very distinct small white point between the 
upper part of the cotyledons; and the radicle 
or germ of the future root, is an equally distinct 
small curved cone at their base. ‘The matter 
of the seed, when examined in its common state, 
appears dead and inert,—it exhibits neither the 
forms nor the functions of life; but let it be acted 
on by moisture, heat, and air, and its organized 
powers are soon distinctly developed. The coty- 
ledons expand, the membranes burst, the radicle 
acquires new matter, descends into the soil, and 
the plume rises towards the free air. By degrees 
the cotyledons become vascular, and are converted 
into leaves, and the perfect plant appears above 
the soil.” This is Sir Humphrey Davy’s general 
description of vascular, or at least of dicotyledon- 
ous germination; and, in all its parts, it is most 
observably exemplified in the bean. When a 
bean seed is placed in humid soil, under a mo- 
derate degree of heat, either in the open air or 
with access to an atmospheric current, its coty- 
ledons soon swell, burst their skin or enveloping 
membrane, and open like a bivalve shell. The 
radicle and the plumule now appear as a small 
oblong body, proceeding from the joint of the 
upened cotyledons; the radicle pushes rapidly 
downward, to elongate and ramify itself into the 
stem and fibres of the root; and the plumule 
rises upward, carrying the cotyledons along with 
it, and exerting so mighty a mechanical force as 
easily to pierce the soil, and even, if necessary, to 
perforate or split asunder considerably cohesive 
clods. All this commencing growth of both the 
radicle and the plumule is effected by the decom- 
posing power of moisture, air, and heat, upon a 
portion of the albuminous matter of the coty- 
ledons, and by the assimilation of the products 
of the decomposition into the substance or organ- 
ism of the nascent root and stem. The swelling 
cotyledons obtain oxygen by the imbibition of 
moisture and air; they give up a portion of their 
carbon to combine with this oxygen, and to go 
off with it in the gaseous form of carbonic acid ; 
and they, in consequence, are, to a large degree, 
converted into a mild, milky, highly nutritious 
fluid, which is drunk up by the minute nascent 
vessels of the radicle and the plumule, and serves 
at once for the support of life, the increment of 
substance, and the full discharge of every organic 
function. The soil yields no aliment or influence 
whatever toward the nascent growth, but serves 
merely for the retention of moisture, the moder- 
ating of heat, and the mechanical anchoring of 
the root ; and if it have been either ill pulverized 
or subsequently trodden, it offers an amount of 
resistance which much of the young plant’s power 
is expended in overcoming. When a footpath is 
led across a field newly sown with beans, or when 
large indurated clods remain unbroken by the 
tillage, the nascent stem often makes long spiral 
evolutions in attempts to worm its way to the 
surface, and the cotyledons are drawn after it 
into the crevices which it makes, and sometimes 
are there held tight till released by the fall of rain. 
While the oxygenic action within the cotyledons 
is in progress, and while their originally hard | 
substance is in consequence undergoing transmu- 
tation into the alimentary fluid, new and minute 
vessels are formed throughout to convey that 
fluid from every part of them to the growing 
radicle and plumule ; and, at length, when the 
radicle is fairly formed into a young root, with its 
fibrous ramifications and its absorbing spongioles, 
—when the plumule rises above the soil, enjoys 
the influences of the open air, and assumes all 
the offices of a young stem,—when, in one word, 
the plant has passed out of its nursling condition, 
and has acquired the organs and the position for 
feeding itself with all requisite elements from the 
soil and the atmosphere, the cotyledons cease to 
yield nourishment, emerge above the soil, change 
into seed-leaves, and begin to assist the new 
mode of growth by elaborating the radical sap 
with the atmospheric gases. Who can contem- 
plate this wondrous process, without observing 
both solemn and delightful evidences of the exist- 
‘ence, wisdom, and power of the all-benevolent 
Creator ? 
Farm-cultivation of the Bean.—The south of 
