THE WATER LILY.

ON THE PECULIAR GROWTH OF THE WATER LILY (NELUMBIUM LUTEUM, Willd.)

Read before the Illinois Natural History Society, June, 1860.

By FREDERICK BRENDEL, of Peoria, Illinois.

EXPLANATION OF THE PLATE.

Fig. 1—The ovary longitudinally divided.

Fig. 2-The seed longitudinally divided, showing the primordial leaves (a,) and the radicle (b,) one cotyledon (c,) and the bony pericarp.

Fig. 3-The young plant produced by the seed.

Fig. 4-The flowering plant produced by a bud: a the rootstock, b the outer scale of the bud; through the base of it passeth the stipule, (d,) and the terminal

bud of which is to be seen the prolongated stem, (e.) Through the base of the stipule generally passeth another bud, prolongated into a runner; c, the inner scale of the bud, protecting the leaf and the flower bud; f, the leaf-this, measuring sometimes two feet in diameter, and the flower, (g) are, in proportion to the rest of the drawing, many times too small. The petiole and peduncle are rough, with black tubercles.

Fig. 5-A cut of the stem. The stem, rhizoma or runner, however we call it, has an internal structure more like the endogenous plants. Cylindrical cavities, generally 8 to 9, in the peduncle 6, in the petiole 4, larger ones and many interstitial smaller ones run side by side along, sometimes interrupted by tender diaphragmas. These cavities run only from one nod or rootstock to the other, the rootstocks being solid. The four larger channels of the peduncle are continuous, with two larger and two smaller cavities in the base of the leaf, indicated on the upper surface by four yellowish-green spots. The cavities again continue in smaller channels, which run on both sides of the nerves to the periphery of the leaf.

Fig. 6-The diaphragma magnified, showing a beautiful net-like structure.

Fig. 7-The diagram as constructed by Trecul: a, the leaves; b, the axillary stipules the extrafoliary stipules; d, the abortive stipule; e, the abortive leaves.

C,

The Water Chinquapin (Nelumbium luteum, Willd.,) a plant of a very peculiar growth, which is common in our Western ponds and lakes, belongs to the Nelumbo family, of which Nelumbium is the single genus. This plant-and so, probably, the few other congenial species-differs so much in its growth from other dicotyledonous plants, that Trecul, a French botanist, in a paper read before the Academy of Sciences at Paris, said: "The singular organization of this plant seems to defy all our systems." Yet he makes some efforts to demonstrate that the leaves and stipules, although simulating an anomalous disposition, submit to all the laws of phyllotaxy. It must be remarked here, that Trecul speaks of N. codophyllum, Raf., and that this is doubtless the same as N. luteum, Willd., the only species which is known in the Western and Southwestern States.

The fruit of the Nelumbium is a bony nut, half imbedded in cavities of a large spongy obconic receptacle, containing a single seed, which is suspended on a filiform funicle, rising on one side of the nut to the apex. A second ovulum in the ovary is abortive, the funicle of which rises on the opposite side, as to be seen in the ovary at an early state. (Fig. 1.)

When the seed is germinating the radicle and the cotyledons do not come forth like in other seeds, but rest in the nut, which is generally laying on the surface of the mud, below the water. The primordial leaves are already highly developed in the seed, (Fig. 2,) bent down on the inside of the petiole, and inclosed in a very tender membranous, hood-like sheath. When the stem has left the nut, the petioles of the obicular peltate leaves, rolled inward from two sides, rise on their prolongated petioles, and, unfolding, float on the surface of the water.

In the axil of the second leaf there is a stipule, which envelops the next, and so on to the fourth or fifth leaf, the stipule of which envelops the terminal bud. The first four or five leaves, alternating on two opposite sides, are very close together; then the prolongated stem, with the terminal bud, runs into the mud, rooting there, and sending up one leaf, which is provided with three membranaceous protective organs, one axillary right as on the preceding leaves, and two others, which Trecul calls extrafoliary stipules -one behind the leaf, protecting the same, and a second below on the opposite side, which envelops the whole. The terminal bud passeth through the latter, piercing it at the base, and produces at a distance a leaf on the upperside, and so on. Now, this one-sided distribution of the leaves, when the first leaves are bifarious, and the number of stipules differing in the young and in the older plant, astonished the mind of Mr. Trecul, and endeavoring to solve the question he relied on the following teleological argumentation:

"The two primordial leaves need no protection, except that of the cotyledons and a thin hyaline membrane covering both together, like a miter. The following leaves need a protection, and so we find one stipule in the axil of the second, third, fourth, and

sometimes the fifth leaf; the merithalls being very short, one stipule is sufficient. But afterwards, when the rhizoma descends into the mud to a depth of twelve to fifteen inches, the merithalls grow longer before the terminal leaf has acquired strength enough to resist the action of destroying external influences-f. i., fermentation of organic matters. Now, the axillary stipule, as it covers only the lower part of the merithall, is insufficient; nature prevented destruction by providing the upper extremity of every internode with two supplementary stipules. But nature works according to fixed laws, and there is no harmony between the early and the later state of growth-the first four or five leaves are distichous; the following which are provided with three stipules, appear only on the upper side of the rhizoma." Torestore accordance with these different arrangements, Trecul supposes that the two extrafoliary stipules are the axillary stipules of abortive leaves, and that a third leaf and its stipule is abortive, and all these organs are abortive because nature did not want them. Teleology is generally founded upon hypothesis, and should be abolished in natural sciences. Cool observation relying upon facts leads on a weary but sure way, when hypothesis leads too often astray. Desirous to find a convenient explanation, we are induced by the slightest probability to believe without sufficient evidence. It seems to me that Trecul, to save a system, which in this case is not at all in danger, mingled entirely different things. The prolongation of the stem from leaf to leaf in the older plant is not a merithall, but a runner with a terminal bud, the origin of a new individual, consisting of a solid rootstock, and producing one leaf, one flower, and new runners, and the so-called extrafoliary stipules are the scales of the bud. The distribution of the leaves in the whole concern of connected individuals has nothing to do with the laws of phyllotaxis. The arrangement of the leaves in our plant is distichous in the individuals produced by the buds, as well as in those produced by seeds that proves the position of the scales of the bud. The difference is, that the former produces a fructiferous scape and only one leaf; the latter produces four or five leaves and no fruit, but only a terminal bud, mediating the propagation in a secondary form. This reminds slightly of the alternate generation of some invertebrate animals.

In this way we need not the very ingenious, but too fictitions, explanation of Trecul; unexplained is only the want of the stipule in the axil of the first leaf. We say, better we do not know the reason, than to explain its absence by the hypothesis that nature did not want it.