AMERICAN AGRICULTURIST 
277 
THE ATMOSPHERE THE GREAT RESERVOIR OF 
FOOD. 
“It is only the girdling, encircling air," 
says a writer in the N>>rth British Review, 
“ that flows above and around us, that makes 
the whole world kin. The carbonic acid 
with which to day our breathing fills the air, 
to-morrow seeks its way round the world 
The date trees that grow around the falls of 
the Nile will drink it in by their leaves ; the 
cedars of Lebanon will take it in to add to 
their stature ; the cocoa nuts of Tahita will 
grow rapidly upon it; and the palms and 
bananas of Japan will change it into flowers. 
The oxygen we are breathing was distilled 
for us some short time ago by the magnolias 
of Susquehanna, and the great trees that 
skirt the Orinoco and the Amazon—the giant 
rhododendrons of the Himalays contributed 
to it, and the roses and myrtles of Cash- 
mere, the cinnamon tree of Ceylon, and the 
forests older than the flood, buried deep in 
the heart of Africa far behind the Mountains 
of the Moon. The rain we see descending 
was thawed for us out of the icebergs 
which have watched the Polar star for ages ; 
and the lotus-lillies have soaked up from the 
Nile, and exhaled as vapor, snows that rest¬ 
ed on the summits of the Alps.” 
“The atmosphere,” says Maun, “which 
forms the outer surface of the habitable 
world, is a vast reservoir, into which the 
supply of food designed for living creatures 
is thrown—or, in one word, it is itself the 
food in its simple form of all living crea¬ 
tures. The animal grinds down the fibre 
and the tissue of the plant, or the nutritious 
store that has been laid up within its cells, 
and converts these into the substance of 
which its own organs are composed. The 
plant acquires the organs and nutritious 
store thus yielded up as food to the ani¬ 
mal, from the invulnerable air surroundiug 
it. But animals are furnished with the 
means of locomotion and of seizure—they 
can approach their food, and lay hold of 
and swallow it: plants must await until their 
food comes to them. No solid particles find 
access to their frames : the restless ambient 
air, which rushes past them loaded with the 
carbon, the hydrogen, the oxygen, the water 
—everything they need in the shape of sup¬ 
plies is constantly at hand to minister to 
their wants, not only to afford them food in 
due season, but in the shape and fashion in 
which it alone can avail them.” 
Ice Houses. —We had occasion some years 
ago to make some inquiries on the subject 
of ice-houses of Mr. N. J. Wythe, of Cam¬ 
bridge, Mass , who planned many of the ex¬ 
tensive commercial ice-houses near Boston. 
Mr. W. constructs his ice houses all above 
ground, with double walls or frames, as de¬ 
scribed by our correspondent, except that the 
space between the two walls is 2i feet at the 
bottom and 2 feet at the top ; the spaces are 
filled with tan or saw-dust, but charcoal is 
better, and a thickness of 13 inches we should 
suppose sufficient to keep ice well. Mr. 
Wythe sets the posts which are to form the 
double walls or frames of his house in the 
ground. 
The bottom of the house, he says, should 
be filled about a foot deep with blocks of 
wood; these are leveled and covered with 
wood shavings, on to which a strong plank 
floor is laid to receive the ice. Upon the 
beams above the ice a tight floor is laid and 
covered several inches deep with dry tan or 
saw dust. The roof of the house should 
have a considerable pitch, and the space be¬ 
tween the upper floor and the roof should be 
ventilated by a littice window at each cable- 
end, or something equivalent, to pass out the 
the warm air which will accumulate beneath 
he roof .-—Louisville Journal. 
Hartiniltunl JUpartment, 
HYBRIDIZATION OF PLANT3. 
A FEW PLAIN EXPLANATIONS FOR TYUuS. 
The word hybridization occurs very fre¬ 
quently in agricultural journals, and we 
imagine that all articles with this heading are 
passed overby many readers, simply because 
they are not acquainted with the first princi 
pies of the subject. We were intending to 
write out a brief explanation of these princi 
pies, but we find at hand a very good article on 
the subject in the Ohio Farmer, written by 
Prof. Cassels, of Cleveland, Ohio, who is 
considered an excellent botanist : 
Few subjects within the range of vegetable 
physiology possess as much interest, either 
theoretically, or practically,as that of hybrid¬ 
ization, or the production of plants by sexu¬ 
al inoculation, partaking more or less of the 
characteristics of two distinctspecies. And 
perhaps there are none whose piocreative 
principles are involved in greater obscurity 
Moreover, this interest is still further in¬ 
creased from the fact, that this is the only 
method by which hybrids are produced. 
That the tyro in botany may the better 
comprehend the modus operands of producing 
these crosses, and some of the principles con 
nected with their existence, it will be neces¬ 
sary to refer here to the manner by which 
the seeds of plants are produce .1 in their nor¬ 
mal state. 
A large proportion of plants contain the 
male and female organs of procreation in the 
same flower, the central portion being that 
of the female, or pistil, immediately sur¬ 
rounded by the male organs, or stamens, ail 
within the flower. The lower portion of the 
pistil is the ovarium , or seed vessel. About 
the time the plant blossoms, the ovarium 
contains ovules, the rudimentary seeds; 
these are vivified by being inoculated with 
the granules of the pollen, which is produced 
by the anthers , or upper portion ofthestam- 
mens. This is effected in the following man¬ 
ner ; soon after the full expansion of the 
flower, the upper end of the pistil, stigma, 
becomes covered with a glutinous substance, 
on which the pollen fall from the anthers 
and adhere; immediately these pollen burst 
and emit a mucoid liquid, in which are mole¬ 
cular bodies, the supposed vivifying agents 
of the ovules. These pass down through the 
substance of the pistil until they come in 
direct contact with the ovules, which in due 
time become perfect seeds; and at the point 
of inoculation is lodged the embryoti • plant 
Those ovules not thus inoculated, remain 
unchanged in the seed vessel, and are in¬ 
capable of germination and growth; such 
are often met with in pea pods. 
Nature, generally true to her trustincaus 
ing each plant to “ yield seed after its kind," 
occasionally permits the pollen of one spe¬ 
cies to be transferred to the stigma of anoth¬ 
er, resulting in the formation of seeds, yield¬ 
ing plants in many respects essentially dif¬ 
ferent from either parents—these are hybrids. 
The extent of these deviations can not be 
very easily ascertained, although I am strong¬ 
ly inclined to the opinion that it is much 
more frequent than most botanists are wil¬ 
ling to allow, as we often hear of new spe¬ 
cies of plants being discovered, which sub¬ 
sequent investigations ascertain to be hy¬ 
brids. Yet, from known facts, the conclu¬ 
sion is irresistible, that there are well de¬ 
fined limits to the existence of these crosses, 
in order that the purity of the races may re¬ 
main as originally impressed on them by 
their Creator ; but where these boundaries 
are, or upon what basis they exist, has not 
yet been ascertained. 
Some able botanists have supposed that 
the same law regulates the production and 
subsequent fertility of hybrids, in both the 
inimal and vegetable kingdoms. To a cer¬ 
ium extent this opinion may tie correct, t ut 
it is well known that s- minal perpetuation 
extends through a greater scries of genera¬ 
tions among plants, than among the animal 
trines; while at the same time they seem to 
admit of a wider range of crossing. It ought 
to be recollected, however, that this princi¬ 
ple is not intended to recognise the inter¬ 
mixture of mere varieties of the same spe¬ 
cies in either kingdoms, such as take place 
among the endless varieties of peas, corn, 
&c., or among our domestic fowls, dogs, 
&e.,but to those of distinct species. 
The limits, too, of seminal propagation 
among hybrid plants, are more indefinite— 
so far as known—than among animals; al¬ 
though, in,this respect, they are exceeding¬ 
ly variable. Titus, a hybrid, of intermediate 
parental characteristics, may be obtained, 
perfect in all its vital functions, and fully 
susceptible of propagation by subdivisions, 
but entirely deficient in the powers of per¬ 
fecting its seeds. In other instances, if com¬ 
plete sterility is not manifest, the progeny is 
puny and sickly, rarely extending beyond 
the third or fourth generation, unless re¬ 
inoculated by a healthy staminate plant. 
Hybrids are supposed to partake of the 
peculiarities of the staminate plant in their 
floral developments, while in their foliage 
they more closely resemble the pistilate 
parent. A knowledge of this is of much 
value to the practical hybridizer. 
The most important practical points con¬ 
nected with hybridization are, which plains, 
in common cultivation, will intermix, and 
which will not? and how these points may 
be determined ; for one of the grand secrets 
in the successful cultivation of all plants 
raised from seeds, depends on their purity 
and perfection. And when intermixture is 
effected, deterioration and sterility will soon¬ 
er or later follow. 
Unfortunately this subject, although of 
vast importance to all cultivators, is still in¬ 
volved in doubt and uncertainty, and nothing 
has yet been developed which can be used 
with certainty in practice. The priciples 
controlling and regulating this action, have 
hitherto eluded detection, and all that is 
known on the subject is mere speculative 
conjectures, based on very limited observa¬ 
tion. 
The Dean of Manchester, who has de¬ 
voted more lime to the subject than any 
other cultivator of hybrids, is firm in the be¬ 
lief that they can not be obtained, by any 
known process, from species of different 
genera; and he adds, “ where such hybrids 
have been reported, it is presumptive evi¬ 
dence that the true principles of their classi¬ 
fication have been overlooked.” On the 
other hand, many well defined species of the 
same genus, can not be made to intermix, 
even by our best manipulators. Thu-,Prof. 
Landley has often tried to cross the goose¬ 
berry with the currant, both species of the 
genus Ribes, but without success. He has 
also attempted, with the same result, cross¬ 
ing the apple and pear, both species of Py- 
rus; the raspberry with the blackberry, 
both species of the genus Rubus. He ob¬ 
serves, “ it is hard to say within what limits 
hybridizating may be effected ; and when¬ 
ever attempted, it can only be regarded as a 
game of chance, played between man and 
plants.” 
The general rule adopted by hybridizers 
is, that plants only which are nearly allied, 
ar susceptible nf crossing. But the excep¬ 
tions are so numerous as almost to destroy 
this generality. Thus, the Thuja Jihfurmis 
i- a hybrid between the Red Cedar and the 
American Arbor Vitae; and plants have been 
