January 29, 1885. ] 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
85 
many cases a deep and unhealthy root-action followed by other evils is 
the consequence.— W. Iggulden. 
[Our correspondent has no cause to fear being “ abused ” by us, as we 
consider our space has been occupied by valuable matter from him and 
others in this discussion of an important subject.] 
THE GERMINATION OF SEEDS. 
[A lecture delivered before the Institute'of Agriculture, South. Kensington, March 
31st, 1881, by Professor G-. X. Bettany, M A., B.Sc., F.Ij.S.] 
The subject of the germination of seeds is one in which pure science 
and practical experience come very clo3e together. The agriculturist, 
whether he is concerned chiefly in corn-raising or in fodder-production, 
or whether he takes up the departments of vegetable or root-growing, 
cannot help occupying himself much about seeds. He either wishes to 
produce good seeds, or good plants from seeds. Many, I am sure, 
must have a practical acquaintance with the subject which it is totally 
impossible for me to attain, and it would ill become me to trench on their 
province, and on that of the distinguished Director of this Institute. But 
to the botanist and vegetable physiologist the word germination is full of 
suggestion, combining as it does apparent simplicity with the profouudest 
consequences. 
The botanist thinks of the young plant hidden in the seed in a state of 
rest from which it has to be awakened, the passive to be made active, the 
dry to become moist. The physiologist, knowing the condition of the 
ripe seed and that of the growing plant, feels the force of the contrast 
between the two, and the word which to him is most significant in con¬ 
sidering the work done is that which indicates agitation and active change 
—namely, ferment. What the changes are which the plant undergoes in 
germination, and how they are produced, is in effect the subject of this 
lecture. 
First, as to the structure of ,the seeds) which we want to germinate. 
Without going at all into the processes by which they are formed, let us 
take them as ripe seeds—smaller or larger masses separated from a parent 
plant, capable of producing, under favourable conditions, a plant like the 
parent in all essentials, though it may difEer in minor points—in height, in 
number of leaves, in weight, &c. 
The true seed of a flowering plant is one of the features by which it is 
most markedly characterised, so that it would be possible by that alone to 
be certain that it was not the product of one of the non-flowering plants, a 
Fern, a moss, a Mushroom, or a Seaweed. The seed of a flowering plant 
is a more advanced structure than the spores which the non-flowering 
plants produce ; it contains within itself a miniature or embryo plant 
which has already made some progress in development, and manifests in 
most cases those distinctions into parts which are of prime importance— 
namely, root, stem, and leaves. 
Such a seed as the Bean, when ripe, contains nothing of importance 
except the young plant. When the skin is peeled off, the rest of the seed 
readdy falls into two divisions; yet these are not totally separate, but 
connected at one side, near the spot where the seed was fixed to the pod. 
These two large lobes, each being nearly one-half of the seed, looking 
extremely unlike ordihary green leaves, are yet, in a botanical sense, the 
first two leaves of the plant—the seed-leaves, often called cotyledons. 
And from this peculiarity of having two equal seed-leaves fixed opposite 
one another to the rudimentary stem, the great proportion of our flowering 
plants, including the Cabbage and Turnip tribe, the Rose and Apple family, 
the pulse and Clover group, the Mangel and the Oak, are called dicoty¬ 
ledons. 
At the point where the two seed-leaves are fixed there is a little stem, 
which is continued one way (pointing towards a little hole in the seed- 
coat), into a cone-shaped growth, the radicle or commencing root. 
Passing in the opposite direction is a little portion of stem bearing a few 
very small leaves. These are flattened and folded together, so that they 
lie snugly between the seed-leaves near their edge. 
Now this represents the plan of all the seeds of what may be called 
the highest kind, where the structure is the most advanced. We meet 
with great differences in the size of the seed-leaves as well as varieties in 
their contents. They are sometimes found folded double or even treble, 
as in various members of the Cabbage tribe. 
But there are many seeds among those with two seed-leaves which 
have not proceeded so far towards simplicity of structure. In addition to 
the minute rudimentary plant, they may have a store of nutriment 
between their thick seed-coats and the small embryo ; and this in many 
plants constitutes the main bulk of the seed, as in the Carrot and Parsnip. 
It has often been called albumena—bad term, because it has a definite 
chemical meaning, whereas the substance to which it is applied in seeds 
has a great variety of chemical composition. I will speak of it only as 
the embryo food. It is the store upon which the young plant is at first fed. 
The main difference between the Bean and the Carrot seed is that the 
young Bean plant has eaten up all the embryo food, while in the Carrot 
seed the embryo is small, and a quantity of embryo food remains uncon¬ 
sumed. And thus we consider the Bean as a higher type of seed, because 
its embryo has already got within itself all the food which the parent 
plant afforded it, while the little Carrot plant has its embryo food in large 
part outside itself, and in germinating has to set to work to absorb some¬ 
thing external. 
Our graia plants, as well as the Palms, of which the Date affords a 
familiar specimen, have seeds containing both an embryo and embryo 
food, the latter usually of much greater bulk than the former. Conse¬ 
quently Wheat, Barley, Indian Corn, &e., consists of a much greater 
amount of embryo food than of embryo plant. Then, again, the embryo 
itself is framed on a different plan. We do not meet, in the e grains, with 
a pair of equal seed-leaves or cotyledons. J ust as in the growing Corn we 
find the leaves wrapped up beautifully one within another, so it is in the 
young state. They arise alternately one on one side of the young stem, 
the other on the other, and fold one over another. 
But the first of the young appendages—that which is of most import¬ 
ance in the actual germination—extends, in a seed like Maize, right over 
the rest of the young plant, so as to overlap both the young bud of small 
leaves and the young root, and it is in contact by its outer edge, in its 
whole extent, with the embryo food. It is by means of this surface that 
the young plant feeds upon and absorbs the stored-up food. 
Next, as to what these seeds consist of chemically. As in the entire 
plant, and in the manures or foods necessary for it, these substances can 
be classified as nitrogenous and non-nitrogenous ; and inasmuch as the 
simpler kinds of nitrogenous bodies, ammonia and the nitrates, do not 
become solid deposits in plants, this term “ nitrog nous ” will here 
principally apply to complex bodies, albumen, casein, gluten, fibrin, and, 
speaking generally, proteids, all of which contain carbon, hydrogen, 
oxygen, nitrogen, and sulphur. 
When the seed was advancing to maturity it, of course, included a 
large proportion of these complex bodies, which go to make up the 
living substance or protoplasm of plants. At the end of the drying 
process it is not the case that all this living substance is wasted or de¬ 
composed. After parting with very much of their water, the nitrogenous 
substances appear as dry bands between the starch granules, or as little 
grains, sometimes of no definite shape, sometimes resembling true mineral 
crystals very closely. In one or other of these shapes the nitrogenous 
matter, by which the living plant is to be again started on its course, is 
preserved during the dormant or resting period. Nay, so completely and 
thoroughly is the continuity and descent from the parent plant maintained, 
that the little corpuscles of living substance out of which the future green 
granules of the plant-leaves are to be developed are continuous descend¬ 
ants of corpuscles in the seed of the parent plant, to which the term 
starch-generators is becoming applied. For the main function of the 
green granules in leaves, as of their colourless representatives in store 
organs, such as seeds and tubers and roots, is to form starch and allied 
substances. 
By far the most abundant of the non-nitrogenous constituents of 
seeds is starch, which occurs in the cells of which the cotyledons or 
seed-leaves consist, and in the embryo food, and in the form of countless 
granules, of characteristic shape and size in almost every plant, usually 
packed closely in the cells, with the little spaces between them devoted to 
the alluminous matters just spoken of. I will only reGr to the fact that 
the starch granules consist of layers having slightly different amounts of 
water combined with them ; also, they are not quite simple chemically, 
consisting oE two nearly allied compounds intermingled, giving slightly 
different reactions. 
Very closely connected in per-centage composition is the material of 
which the cell walls are composed—the cellulose membrane. When 
starch is abundant—or something equivalent to it—the cell-membrane is 
thin ; but in some seeds, as in the Date stone, it is extremely thickened, 
so as to form almost the entire mass of the seed, and actually take the 
place of starch as the food store to be drawn upon during germination. 
Yet another kind of non-nitrogenous body has to be mentioned— 
namely, oil. The oils occurring in seeds agree in being composed of 
carbon, hydrogen, and oxygen, and in having comparatively little oxygen. 
Oils are abundant in many seeds which have little or no starch, such as 
the castor-oil seed, rapeseed, linseed. It is found in minute granules 
and in smaller or larger drops in the oells, between the nitrogenous grains 
or particles. 
(To be continued.) 
WINTER DRESSING FRUIT TREES. 
( Continued from page 12.) 
Insects. —We are sometimes asked to believe that potent 
as some insecticides are when applied to the perfect insect, the 
eggs are proof against them, consequently winter dressings are 
practically useless. Practice has, however, proved the value of 
the dressings, as the trees so treated are much freer in the 
ensuing season than those not so treated. There is no doubt 
much to be stated both for and against the practice of winter 
dressing fruit trees, and I will admit that if it is coating the 
bark of trees with a pigment that leaves a thick deposit, it is 
much better left alone, as it really serves as a protection. Every 
cultivator seems aware of the injurious effect of moss and lichen 
on the bark of trees, and yet coats the bark with a pigment 
which seals the pores as effectively as a coating of moss or lichen. 
I have found winter dessings useful, and there can be little 
objection to removing any loose bark from Vines in order that 
the insecticide may be more effectively applied, but any removal 
of even loose bark so as to suddenly expose the inner to severe 
cold must have a bad result from giving a eheck, hence it should 
be done in moderation, and never so as to wound or injure the 
quick. 
After the pruning of frut trees is completed, and before the 
trees are secured to the wall, they should be dressed with an 
insecticide, and there is no better means of doing so than with 
