That part of the carpel called the ovary, which encloses the seed, thickens, and changes into a fleshy substance, which, as the fruit matures, softens, and becomes a juicy, and often delicious pulp; this is the part which we eat in the plum, cherry, apricot, peach, and all which we call stone-fruits. The lining of the ovary at the same time extends, and hardens into the stony case which encloses the kernel, which kernel is the young seed enlarged and perfected. All fruits of this formation are called drupes, as those of the apple and pear form are called pomes, and those of the bramble, and some other tribes, berries. Our woods supply us with two sorts of plum, both edible--the sloe, or blackthorn (_Prunus spinosa_), and the wild bullace (_P. institia_.) Every one knows the sloe, at least every one who has spent any part of his youth amidst woodland scenes; but as there are some who, having been 'all their life in populous cities pent,' know but little of country delights, for their benefit we will describe the growth and appearance of our plants, as well as their qualities, obvious or hidden. The sloe is more frequently seen as a spiny shrub than as a tree; but when the suckers are removed, and the strength of the plant is all allowed to go into one stem, it forms a highly characteristic small tree. In hedges, it seldom exceeds twenty feet in height, but in woods and parks, it often attains to thirty. The wood is hard, and takes a fine polish, but is apt to crack, and is therefore seldom used, except for the handles of tools, and other such purposes. It throws up very long upright shoots, which make excellent walking-sticks; indeed, more are made from this tree throughout Europe than from any other. The dry branches are valuable in forming hedges, and protection for young trees, as well as for other agricultural purposes. The bark is black, whence its name of blackthorn; the blossoms appear before the leaves, and beautify our hedges with their delicate whiteness during the cold month of March, when few other shrubs send forth their blossoms; and this season is therefore called by country-people 'blackthorn winter.' The leaves form a better substitute for tea than any other European plant; and they have been, and are abundantly used in the adulteration of that commodity. The fruit is a plum about the size of a small filbert, of a dark purple hue, coated with a most exquisite blue bloom. The flesh is of a sharp, bitter acid, yet not unpleasant even when raw; when fully ripe, it makes a tolerable preserve, or pudding, and the juice, when well fermented, makes a wine not unlike new port. The sloe, as well as the cherry, and all other plants of its tribe, contains in it a portion of prussic acid; but the quantity is so minute, that there can be no injury derived from the use of either the leaves or fruit of most species. The common laurel (_Cerasus laurocerasus_) contains it in greater quantity than any other kind, but even of this the berries may