232 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
[ March 20, 1884. 
circulates to every part of the plant, much as the blood circulates in the 
animal system. So well are botanists and physiologists agreed upon this 
subject that controversy ha3 nearly ceased. From this we obtain an idea of 
the source of the protoplasm, which originates not only all sports but all 
growth in plant life. 
“Another class of well-established facts which we must understand 
before we approach the subject 'of sports relates to the cell structure of 
plants. All plants originate in, and are composed of, minute cells. Every 
natural plant or tree came from one parent cell, which had the power of 
multiplying itself and building up the whole plant or tree. From every 
parent cell in a plant or tree, whether in root, branch, bud, or leaf, may be 
developed another branch or tree, which will be true to its kind. No natural 
plant or tree can of itself alone ever change its kind. On this fact depends 
the permanency of varieties. Keeping these facts in mind, we will now 
consider the formation of the cells. All writers admit that every cell is 
formed in the cambium by the protoplasm. According to their description, 
the protoplasm is one of the most wonderful agents in the world. They 
assure us that it has an inherent power of motion as persistent and 
independent as the beating of the heart, and even more so, for, while the 
heart is always confined to the same relative spot, the protoplasm changes its 
locality and performs various kinds of motions, and seems to be endowed with 
a wisdom to foresee and plan, and a skill to execute the most varied operations. 
It not only forms the cells, but changes their forms to make tubes and vessels, 
woody fibre, bark, buds and leaves ; secretes the gum, starch, sugar, and all 
the materials that enter into the composition of plants ; produces the most 
delicate blossoms, the most delicious fruits, and finally, to perpetuate its 
kind, inserts in every specimen of fruit a little embryo of itself in the well- 
protected seed. All this is ascribed to the protoplasm. Men witnessing 
this wonderful display of wisdom and skill everywhere seen have 
called it Nature, and bowed in reverence; but let us rather view it as the 
handiwork of the Infinite One, whose wisdom designed, whose power 
executes and upholds, and whose boundless love pervades the whole. Or 
with the poet, exclaim,— 
‘ All are but parts of one stupendous whole, 
Whose body Nature is, and God the soul.’ 
“ But that protoplasm is the agent by which all vegetable growth is carried 
on must be admitted. By the improved microscope we can actually witness 
the wonderful process. We can see the first step toward the formation of a 
cell. We can see the protoplasm in the cambium, as it forms itself into a 
little globe or ball to become the nucleus of the future cell. We can see 
it begin to rotate and take form, as it secretes the substance with 
which it surrounds itself with a cell wall as perfect as the shell of an egg. 
Thus the nucleus, the cell sap, and the cell wall constitute a parent cell. 
The nucleus is simply living protoplasm, which, as soon as the first cell is 
completed, divides itself into two parts, each taking an end of the cell, 
begins its rotary motion, divides the cell wall, and from the half each forms 
a new cell as perfect as the first. Thus from one cell two are formed, each 
to be again divided, and thus on to infinity. But when a sufficient number 
of cells are formed, one above another, a new work commences, with which 
we are particularly interested. The protoplasm in the perpendicular row of 
cells begins to absorb the transverse septa or end walls which are in contact 
with each other; and joining the side walls together forms tubes or sap 
vessels ; then, passes up through the tubes thus formed and uniting, recom¬ 
mences its work of cell-building to complete the plant or tree. It is the 
union of the protoplasm or the contents of these cells as it absorbs the cell 
walls between them and recommences cell-building, that gives the key to the 
origin of sports.” 
(To be continued.) 
THE INSECT ENEMIES OF OUE GAEDEN CEOPS. 
THE CHERRY. 
Though not prepared to give statistics in the matter, I 
venture to assert that the production of British Cherries has 
hardly increased of late so as to rival the production of other 
fruits which are in greater demand than formerly, owing to the 
growth of our population. I do not mean to say that the attack 
made upon the Cherry by some medical authorities on the plea 
of its unwholesome nature has had any notable influence; it is 
rather the effect of a considerable importation of this fruit from 
the continent. Then, again, our Cherry orchards have suffered 
very much in recent years through unfavourable springs; and 
in Kent, doubtless also elsewhere, much damage has been 
done by the severe gales we have had since 1878, many old but 
good-bearing trees being uprooted or losing some of their 
branches. With regard to the insect foes of the Cherry, the 
reports published do not show that they usually cause any great 
loss of fruit. They are, however, somewhat pertinacious, and 
in 1872 and 1873 no little stir was occasioned by the appearance 
and abundance of tbe “ slugworm,” a creature that is one of 
those insects which have naturally a repulsiveness about them. 
We have accused America of sending us a blight, that all 
our efforts cannot entirely free our Apple trunks ; also, and for 
years past, we bave been in fear that the American Potato beetle 
will yet make a settlement here, and some persons have also 
been very positive that the “ slugworm ” came somehow across 
the Atlantic about ten or twelve years ago. It is true that the 
best account given of it was written by Prof. Peck at the close 
of last century, and published in Boston, U.S , but the insect 
(or some of them, for there are various species) was known in 
Europe long before then. Fabricius, Reaumur, and Linneus all 
observed these slimy larvae of sawflies, though in some respects 
they mis-stated their habits and history. Even now we are 
doubtful as to the specific boundaries. The late Edward New¬ 
man, for instance, thought that under the general name of 
Selandria aethiops (figs. 52 and53) might be included the various 
larvae observed in the Pear, 
-1- Sloe, Plum, Cherry, and other 
1 fruit trees. It is certain, how- 
’V ever, the species are more 
Jh numerous than he supposed. 
Thus the Cherry pest, Selan- 
dria or Blennocampa Cerasi, 
is sufficiently marked out 
as distinct; and one of its 
peculiarities is that the full- 
v I | ^ grown grub does notdescend 
I I to the ground, but forms a 
^ gummy cocoon upon a twig 
Fig. 52.—Imago of Selandria setkiops, Newman °f the tree. Within this 
(magnified). the pupa reposes through 
the winter, and it is obvious 
that no amount of syringing is likely to kill it or stop its 
development. . 
The flies emerge during June. Of the female insect the 
entomologist above mentioned writes in his original way—“Her 
first thought is matrimony; her second thought, or instinct, is 
preparing for a family. She is always in mourning; even before 
matrimony she wears the sable garment of widowhood. Her 
head, antennae, body, and legs are almost entirely clothed in 
black. Her wings, otherwise colourless, bear a blackish shade 
across the middle.” Her partner is of similar appearance, and 
in both sexes we find the habit of shamming death when alarmed, 
the fly falling as if insensible, with the limbs closely folded 
together. The eggs are deposited upon the leaves of the Cherry 
in~a small slit made by the parent by means of her ovipositor, 
each separately. It is a singular circumstance that, from their 
having a shell of elastic material, these may be seen to increase 
in size before hatching. From their minute size and pale colour 
Fig. 53.—Larva of Selandria fethiops, Newman. 
the young larvae are hardly discernible by the unaided eye, and 
before long they begin to be coated with the thick slime of 
blackish brown, which originated their popular name. This 
has an unpleasant smell, though not always noticeable. These 
slugworms have, in fact, the numerous feet possessed by most 
larvae of sawflies, by the aid of which they glide slowly over the 
leaves, but these organs and the shape of the body are quite 
hidden by their protective coating. Perhaps owing to this the 
insects escape partially from the attacks of birds. In feeding 
they confine themselves to the upper surface of the leaf, keeping 
near the centre and avoiding the veins. Cherry trees are not 
only disfigured but rendered sickly by a visitation of these larvae, 
upon which syringing and similar modes of treatment have very 
little harmful effect. The best plan of operating upon it appears 
to be that of dusting the leaves well with quicklime directly it 
is observed, as this adheres to the slugworm and speedily kills 
it. In America, however, it is usual to apply powdered hellebore 
mixed with water, which compound is thrown upon the trees 
from above. I would not myself be inclined to advise this 
remedy for general adoption; indeed it might be dangerous at 
the time the fruit is setting, unless washed off very copiously. 
More than one species of aphis occurs upon the Cherry. The 
most abundant and hurtful kind is the too well-known “ black 
fly,” or Aphis Cerasi, conspicuous by its black hue through the 
