By Prof. J. H. MONTGOMERY.

On the terms Annual and Biennial.—There is certainly much ambiguity between the terms annual and biennial. Those plants which germinate in the spring and die in the autumn are not very different from those which vegetate in the summer or autumn and flower and die in the succeeding spring or summer; nor indeed can I see much between them and plants like Agave, which live in a barren state for many years, and then flower once and die. It seems to be only a question of time required to concentrate the requisite energy to produce flowers and fruit. True annual plants may be divided into winter annuals and summer annuals. The former usually store up nutritive matter in the autumn to supply the flowering state in the spring; differing in this from summer annuals. But this is not constantly the case. The Agave is many years doing this. Although this plant flowers only once, we of course ought to have a term to distinguish it from the annuals. There are also the plants which produce stoles rooting at the end, such as the sympodes of Fragaria; in that case the plants are truly perennial. But see such plants as Epilobium, where the buds at the end of stoles alone remain alive during the winter, and produce the plants of the succeeding year; what are we to call these? We usually denominate them perennial. Then how separate them from those which are not aËrial, but go through the same course? Then come such plants as Orchis, where a new tuber is formed by the side of the old one each year, usually at a very short distance from it, but sometimes at some considerable distance, as in Herminium; and the tuber which has flowered dies. The tuber is therefore a winter annual. Of course all these ought not to be confounded with the true perennials, where the same root lives and flowers at least several years in succession. DeCandolle’s terms, mono- and poly-carpic will not do; for they convey another idea. Mono- and poly-tocus, as suggested by A. Gray, are better, but here we do not distinguish between Agave and Brassica. And he has not attempted to distinguish these from Orchis (except by calling them perennial, as we all do), or Orchis from Fragaria. Here is a subject of much interest for those to study who pay attention to such matters.—Journal of Botany.

There is a strange plant with a curious flower growing in the damp valleys of New Granada, called Masdevallia chimaera. It is one of the unique productions of the vegetable kingdom. This plant has a dense cluster of thick leaves; the slender flower stems creep along and flower under the moss or leaves. The flower cup is divided into three lobes, and is whitish in color, with irregular spots of pink. So fantastic is this flower that a writer in La Nature says: “In looking at this strange flower one sees the colors of a nocturnal bird, the form of a large spider in the middle, with two small, piercing black eyes.”

Trees of Lake Chad.—Dr. Nachtigal, in his “African Journeys,” describes some curious trees that grow in the region of Lake Chad. The butter-tree, called in that country toso-kan, bears a green, round fruit, ripening into yellow, about as large as a small citron. This fruit consists of a nut resembling a horse-chestnut in color and in size, and a palatable, fleshy, smooth-skinned covering like a plum. The nut affords an oil, which solidifies under a slight decrease of temperature, and is used throughout North Africa as a substitute for butter. The Parpia biglobosa, of the same region, a leguminous plant, furnishes an excellent food in its seeds, which are eatable while still unripe. The ripe seeds contain a thick, saffron-colored marrow, inclosing black, shining grains. The meal made from them forms, when mixed with water or milk, a pap, which has a sweet and pleasant taste at first, but soon cloys. Relieved with sour milk or tamarind-juice, it forms a dish healthful and enjoyable to all. The wool-tree is the third characteristic tree of the country. It rises straight up, with thick, horizontal branches arranged in whorls, one above the other, and derives its name from its fruit, which bursts like pods of cotton, and discloses a similar mass of fibers, lustrous and soft as eider-down. This “wool” is used in stuffing cushions and mattresses and for the wadding-armor of heavy cavalry. It has the valuable property of never becoming so compact but that it can be restored to its original volume by a short exposure to the sun. The tree is a favorite place of refuge for the negroes in time of danger. Taking their children and goods up with them they secure an excellent natural fortress among the whorls of its limbs.—Popular Science Monthly.

Peach leaves curl and wither because of a fungus growth upon their surfaces. This vegetable parasite often ruins the first crop of leaves and unless they are replaced by a new growth early in the summer the tree is injured, often permanently.