120 
THE GOOSEBERE-Y GRUB. 
of a net. In many trees the outer layers of 
the rind are being continually thrown off by 
exposure to the weather, and their place as 
constantly supplied by the outer layers of the 
liber, so that however diverse in appearance, 
it appears that the structure of these two is 
alike. In the beech, fir, &c. I conceive the 
epidermis is not thrown off. Beneath the 
bark, we perceive the wood, which likewise 
consists of two parts ; the outer is the albur- 
num, or soft wood ; the interior, the duramen, 
or heart-wood ; the latter is usually darker in 
tint, and more compact in texture. These 
parts are composed also of strata or layers, 
which are very visible, as each layer exhibits 
two structures, the inner side of it being com- 
posed of cellular tissue, the outer of ducts and 
woody fibre ; they do not increase in size, but 
a new one is formed every year, between the 
liber and the albtinmm. If we strip the liber 
from a tree in June, we find that it readily 
separates, and that a mucilaginous fibrous 
substance is deposited between it and the 
trunk, which appears to form a layer of 
alburnum on one side, and a layer of liber on 
the other. In the centre of the tree we see a 
ring, or a section of a tube, called the medul- 
lary sheath, or corona, whence proceed radi- 
ating lines to all parts of the circumference, 
forming, when the tree is split, those shining 
satiny bands, so beautiful and conspicuous 
in the maple, beech, and birch. These are 
medullary rays, and serve to connect the 
medullary sheath with the leaves ; the water 
taken up by the roots passing up the spiral 
vessels and ducts of the sheath, through the 
rays into the leaves. Within the corona is 
tlie medulla, or pith, which is composed of 
cellular tissue slightly compressed: it never 
increases in diameter after it is formed, and 
therefore its bulk depends not on the size of 
the tree, but in some measure on the size of 
the twigs ; the ash, butternut, elder, &c. 
which have thick large twigs, having more 
pith than the maple, beech, or elm, whose 
twigs are slender. In some full grown trees, 
its presence is indeed scarcely to be distin- 
guished, the cells having been gradually filled 
up by the juices of the tree. 
" C — Why does a plant die if its bark be 
cut round ? 
" F. — Because the vegetative life resides 
in the liher, and if this be divided, as in 
girdled trees, so that the upper part has no 
contact with the lower, no more buds or leaves 
can be put forth, these being produced from 
the inner surface of the liber. But if it be 
divided in part, that side of the tree whose 
connexion is unbroken will continue to flourish, 
wiiile the portion immediately above the sepa- 
rated bark withers and dies, as may be seen 
in a hundred instances in our forests. 
" C. — I have often wondered at the huge 
globular excrescences that stand out from the 
trunks of some trees, such as the maple, but 
more especially the birch ; sometimes as large 
as a hogshead. Do you know the cause of 
them ? 
" F. — I do not, accurately ; on being cut, 
they present the regular structure of wood, 
surrounded by bai'k, but remarkably twisted 
and gnarled in the grain : in the centre is 
always some cavity or defect. I suspect they 
are either a diseased growth of the tree, like 
wens in animals, or the accumulated layers of 
ages around the base of some broken limb. 
" But we have finished a year ; the seasons 
have completed their annual course since we 
commenced our wild woodland rambles ; many 
subjects of interest have fallen beneath our 
observation ; many phenomena, more or less 
obvious, have occurred to our notice, calcu- 
lated, I trust, to make us wiser and better. 
If they have tended to enlarge our informa- 
tion, to increase our cheerfulness, to calm and 
elevate our minds, to enforce a merciful con- 
sideration towards inferior animals, to open 
before us a wider display of the power, wisdom, 
providence, and benevolence of Him who is 
essential Love, — why, we have not wasted 
our time. But we have seen but a small 
portion of the mysteries of nature ; inex- 
haustible stores yet remain to be unlocked ; 
interesting and unexpected facts, hidden from 
the unobservant, are continually disclosed to 
him who walks through the world with ixw 
open eye. We may possibly undertake another 
course of investigations similar to the one just 
concluded ; new beauties will present them- 
selves to our admiring gaze ; no season is so 
barren but that it possesses charms, either 
inherent or associated, peculiar to itself ; and 
every clime affords ample opportunities for 
the prosecution of these studies. ' Day unto 
day uttereth speech, and night unto night 
showeth knowledge : there is no speech nor 
language, where their voice is not heard.' 
These, too, ' .declare the glory of God,' and 
these ' show forth His handy-work.' This 
fact cannot be too strongly impressed : it 
should never be forgotten that we must not 
rest in the creature, but be led up to tlie 
Creator; and not only perceive His hand, but 
fear Him, trust in Him, and love Him." 
THE GOOSEBERRY GRUB. 
Probably few persons who have a garden 
of fruit trees, are entirely ignorant of the de- 
predations of what is called the gooseberry 
caterpillar or grub, although they may be 
ignorant of the cause of the damage. It is 
not unusual, where no means have been eni- 
ployed to check their depredations, to see 
