only can live. Although the leaves of the Droseras at a hasty glance do not appear green, owing to the purple color of the tentacles, yet the superior and inferior surfaces of the blade, the stalks of the central tentacles, and the petioles contain chlorophyll, rendering the best of evidence that the plants obtain and assimilate carbon dioxide from the air. But when the poverty of the soil where these plants grow is considered, it is at once apparent that their supply of nitrogen would be exceedingly small, or quite deficient, unless they had the power of obtaining it from some other source. From captured insects this important element is largely obtained, and thus we are prepared to understand how it is that their roots, which consist of only two or three slightly divided branches, from one-half to one inch in length, and furnished

ROUND-LEAVED SUNDEW.
Leaves Acting as Stomachs.

with absorbent hairs, are so poorly developed. From what has been stated it would seem that the roots but serve to imbibe water, but there is no doubt that nutritious matters would also be absorbed were they present in the soil.

With the edges of its leaves curled so as to form a temporary stomach, and with the glands of its closely-inflected tentacles pouring forth their truly acid secretion, which dissolves animal matters that are subsequently absorbed, Drosera may be said to feed like an animal. But, unlike an animal, it drinks by means of its roots, and largely, too, for it would not be able to supply its glands with the necessary viscid fluid. The amount needed is by no means an inconsiderable quantity, as two hundred and seventy drops may sometimes be exposed during a whole day to a glaring sun. Such a profuse exudation implies preparations for hosts of insect visitors. In this Drosera has not miscalculated. Its bright pink blossoms and brilliant, glistening dew lure vast numbers of the smaller kinds, and the larger ones, too, to certain death. But the wholesale destruction of life that goes on is much in excess of what the plant requires for food. While the smaller flies remain adherent to the leaves, affording them the needed aliment, the larger insects, after death, fall around the roots, where they decay and fertilize the soil with nitrogen, which doubtless through the proper channels makes its way into the body of the plant, thus helping to give it tone and vigor. There are times when these plants work better than at others, but whether this is caused by the electrical condition of the atmosphere, or the amount of its contained moisture, is a question which science has not positively determined.

Drosera longifolia folds it leaves entirely around its victim, from the apex down to the petiole after the manner of its vernation, but in Drosera rotundifolia, whose marginal tentacles are longer, the tentacles simply curve around the object, the glands touching the substance, like so many mouths receiving nourishment. Experimented upon with

raw beef, the tentacles of healthy leaves, from within to without, but in periods of time varying from six to eight or nine hours, clasp firmly the beef, almost concealing it from view. Equally vigorous leaves, however, made no move towards clasping a bit of dry chalk, a chip of flint, or a lump of earth. Bits of raw apple cause a curving of the tentacles, but very few of the glands are seen touching them. It would seem, therefore, that these plants are really carnivorous, preferring animal substances, which they, by the aid of some ferment analogous to pepsin, which is secreted by the glands, are able to absorb. A minute quantity of already soluble animal matter is the exciting cause, and this must be taken in by the glands, or there is no secretion of the fermenting material.

In all ordinary cases the glands alone are susceptible to excitement. When excited, they do not themselves move or change form, but transmit a motor impulse to the bending part of their own and adjoining tentacles, and are thus carried towards the centre of the leaf. Stimulants applied to the glands of the short tentacles on the disc indirectly excite movement of the exterior tentacles, for the stimulus of the glands of the disc acts on the bending part of the latter tentacles, near their bases, and does not first travel up the pedicels to the glands, to be then reflected back to the bending place. Some influence, however, does travel up to the glands, causing them to secrete most copiously, and the secretion to become acid, just such an influence as that which in animals is transmitted along the nerves to glands, modifying their power of secretion, independently of the condition of the blood-vessels. Over organic substances that yield soluble matter the tentacles remain clasped for a much longer time than over those not acted upon by the secretion, or over inorganic objects. That they have the power of rendering organic substances soluble, that is, that they have the power of digestion, is no longer a question of dispute. They certainly have this power, acting on

albuminous compounds in exactly the same manner as does the gastric juice of mammals, the digested matter being afterwards absorbed. In animals the digestion of albuminous compounds is effected by means of a ferment, pepsin, together with weak hydrochloric acid, though almost any acid will serve, yet neither pepsin nor an acid by itself has any such power. It has been observed that when the glands of the disc are excited by the contact of any object, especially of one containing nitrogeneous matter, the outer tentacles and often the blade become inflected, the leaf thereby becoming converted into a temporary cup or stomach. The discal glands then secrete more copiously, the secretion becoming acid, and, moreover, some influence being transmitted by them to the glands of the exterior tentacles, causing them to emit a more abundant secretion, which also becomes acid. This secretion is to a certain extent antiseptic, as it checks the appearance of mould and infusoria, and in this particular acts like the gastric juice of the higher animals, which is known to arrest putrefaction by destroying the microzymes.

With animals, according to Schiff, mechanical irritation excites the glands of the stomach to secrete an acid, but not pepsin. There is strong reason to believe, too, that the glands of Drosera, which are continually secreting viscid fluid to replace the losses by evaporation, do not secrete the ferment proper for digestion when mechanically irritated, but only after absorbing certain matters of a nitrogeneous nature. The glands of the stomachs of animals secrete pepsin only after they have absorbed certain soluble substances designated peptogenes, showing a remarkable parallelism between the glands of Drosera and those of the stomach in the secretion of their appropriate acid and ferment.

Not only animal matter, but also the albumen of living seeds, which are injured or killed by the secretion, are acted upon by the glands of Drosera. Matter is likewise absorbed from pollen, and from fresh leaves. The stomachs of

vegetable-feeding animals, as is only too well known,

possess

a similar power of extracting nourishment from such articles. Though properly an insectivorous plant, but as pollen, as well as the seeds and leaves of surrounding plants, cannot fail to be often or occasionally blown upon the glands of Drosera, yet it must be credited with being to a certain extent a vegetable feeder.

That a plant and an animal should secrete the same, or nearly the same, complex digestive fluid, adapted for a similar purpose, is a wonderful fact in physiology, but not more remarkable than the movements of a tentacle consequent upon an impulse received from its own gland, the movement at the bending place of the tentacle being always towards the centre of the leaf, and so it is with all the tentacles when their glands are excited by immersion in a suitable fluid. The short tentacles in the middle part of the disc, however, must be excepted, as these do not bend at all when thus excited. But when the motor impulse comes from one side of the disc, the surrounding tentacles, and even the short ones in the middle of the disc, all bend with precision towards the point of excitement, no matter where it may be located. This is in every way a remarkable phenomenon, for the leaf appears as if endowed with animal sense and intelligence. It is all the more remarkable when the motor impulse strikes the base of a tentacle obliquely to its flattened surface, for then the contraction of the cells must be restricted to one, two or a very few rows at one end, and different sides of the surrounding tentacles must be acted on that all may bend with precision to the point of excitement. The motor impulse, as it spreads from one or more glands across the disc, enters the bases of the surrounding tentacles, and instantly acts on the bending place, but does not first proceed up the tentacles to the glands, causing them to reflect back an impulse to their bases, although some influence is sent up to the glands, whereby their secretion is. soon increased and rendered acid. The glands, being thus