This species has been found in the greatest abundance on certain islands on the coast of Maine, and also on the lower parts of Cape Cod and Cape Ann, as well as in Canada and Nova Scotia. It is unquestionably identical with the European species, and is supposed to have found its way to this country through commercial intercourse, though it seems strange that, while in the old country it is found near the habitations of men, in this country it occurs only upon the most uninhabitable islands.

In England, this species is very abundant, and forms a favorite food for the thrushes and blackbirds. Ralph Tate, the author of a very readable book on the land and fresh-water mollusks of Great Britain, says: "In a country walk one may frequently see a large stone surrounded by fractured snail-shells; these are the slaughteringblocks whereon the poor snail is sacrificed for the welfare of our songsters and their young progenies. The shells are very systematically broken. The bird strikes the shell upon the stone in such a position as to expose the principal mass of the snail at about the commencement of the last whorl." In France, this species is used as an article of food.

Figs. 17, 18.

HELIX ALTERNATA Say. (Figs. 17, 18.) Shell flattened, heavily striated; light horn-color, with dark brown bands and spots arranged obliquely across the whorls. Aperture, when viewed from below, nearly circular. Lip simple and sharp. Whorls six in fullgrown shells. In young specimens the shell is carinated, that is, the outer whorl is keeled or angulated, instead of rounded. The base of the shell is lighter in

color than the upper surface. Colorless shells are sometimes found. Diameter about one inch.

This is one of the most common species of snail in New England, though occurring only in certain localities; it generally occurs in great numbers. It is found in forests, and sometimes in open fields in damp situations. On islands they often occur in the greatest profusion. When in captivity, they lie buried most of the time under the moist earth, and appear to suffer more from the want of moisture than other species.-To be continued.

PARASITIC PLANTS.

BY G. D. PHIPPEN.

Fig. 1.

To persons familiar with the principles of cultivation, and with more or less knowledge of our native plants, the fact that there are tribes of plants in other regions of the earth, that, without any attachment whatever to the soil, grow and produce flowers of the most novel form and brilliancy of colors, seems wonderful in the extreme. Such are the Epiphytes, or air-plants of the tropics, whose seeds, lodging on the branches of living or decayed trees, or even upon the very rocks, readily vegetate, and draw from the surrounding atmosphere the constituents of their growth.

This is accomplished chiefly through their roots, as in

other plants; and as they are found to increase with much greater luxuriance in the recesses of the forest, by the banks of streams, in a sultry, humid atmosphere, we see less difficulty in comprehending the possibilities of their growth and the economy of their being; indeed, their nature is now so well understood, that they are cultivated with ease in our conservatories.

We do not, however, intend to write of air-plants, as our country produces none; but we have, among our native plants, those whose methods of growth are perhaps scarcely less novel and wonderful; such as our parasites, which derive their nourishment from other living plants to which they adhere,-depending upon the leaves and roots of such plants for the necessary contact with the atmosphere and the soil.

The name Parasite is of great significance, for such plants are robbers in the fullest sense, and live solely at the expense of their neighbors.

The most marked example in this region of such anomalous plants is the Dodder. Our species, the Cuscuta Gronovii (C. umbrosa Torrey, or C. vulgivaga Englemann) is as strongly marked, and more widely distributed than either of the other American species.

The genus Cuscuta has generally been appended to the Convolvulacea, or the Convolvulus tribe, which consists chiefly of twining plants, and have regular monopetalous pentandrous corollas, and two to four-celled capsules, with large seeds. This order is well represented by the Cypress vine and the Morning-glory.

The Cuscutas have no leaves, for these plants need none; all the necessary functions of leaves, as has been stated, being performed by the leaves of other plants on which they grow. They have, however, a few minute

scales in alternate succession, which are in place of leaves, and from their axils spring the branches. (See Fig. 1.) Although so anomalous as these plants are supposed to be, yet the right of being perfect plants must be conceded them, and they are properly assigned a place with other Convolvuli.

Eight or nine species grow freely in this country, two of which are found in New England.

C. epilinum, or the Flax Dodder of the old world, mentioned by Gerard and more ancient writers, is naturalized here to some extent. It is said to grow only upon flax, to which it is a great pest, spoiling large quantities. It was noticed by Dr. Cutler as being destructive in his time; but as that useful plant is now seldom cultivated in this region, the Flax Dodder is but rarely detected. A monograph of the American species, prepared by Dr. George Englemann, of St. Louis, can be found in Silliman's Journal, vols. 43, p. 333, and 45, p. 73.

Under the name C. Americana, the various native species were for a long time confounded. The botanical text-books tell us that the seeds of this strange plant germinate in the earth in the ordinary manner, throwing downward a root into the soil, by which for a short time the tender plantlet is sustained, until it elongates its thread-like stem sufficiently to reach some foster-plant, around which it immediately twines, and into whose tender bark it thrusts aerial roots, which feed upon its juices; after which, no longer needing attachment to the soil, the primitive root withers away.

After many times plucking the cord-like stems of this plant, and noticing the decisive development of its flowers and seed (for they are as perfect as upon leaf-clad plants), we resolved to prove, with our own