In

time, and still more during past ages. accordance with this acknowledginent, a wide range of scientific research still remains to be undertaken, and religious thought can have nothing but friendly interest in the work, as it may well be assured of drawing thence fresh contributions of great value for higher speculation concerning the government of the universe.

* Origin of Species, 6th. ed. chap. iv. p. 100.

LECTURE V.

RELATIONS OF LOWER AND HIGHER ORGAN

ISMS.

FROM the general aspects of the theory of species, we pass to the consideration of distinct groups of organism, with the view of ascertaining their relations to each other. In doing so, it is better to begin at the lower end of the scale, leaving for a more advanced stage of inquiry the higher types of organism. In this department of the subject, special obligations are due to the wide range of investigations either occasioned or stimulated by the theory of evolution. For, whatever may be the ultimate award passed on this theory, there will be a unanimous recognition of the great value to science attending on the varied forms of inquiry stimulated by the writings of Mr. Charles Darwin. And one obvious and strong reason for such acknowledgment is that so many of the results of these researches have an inherent value quite dis

tinct from their testimony in favor of the theory that the struggle for existence is the principal factor in the origin of new species.

One of the most interesting fields of observation thus opened, is that concerned with. the fertilization of plants by the intervention of insects and birds. A beginning in this department was made by the German naturalist, Christian Konrad Sprengel, who published in 1793 the report of his observations. In this he has been followed by Darwin, in 1862; by Dr. Hooker, Professor Asa Gray whose contributions appeared in the American Journal of Science and Art in 1862, and 1863, Moggridge, Fritz Müller, and Sir John Lubbock. The facts now accumulated, rank as an important contribution to botany and zöology, and naturally fall within the circle of recent advances to which it is desirable that attention be turned.

The general result is one of great interest, as illustrating a striking degree of interdependence between lower and higher organisms, the vegetable and animal kingdom. contributing to each other's subsistence and propagation. Flowers present special attractions to insects flying around, alluring them

by varied colors, and providing for them by secreting stores of honey; on the other hand, these insects (flies, bees, wasps, etc.), seeking the honey which satisfies their wants, at the same time carry the pollen from one flower to another, thus providing for the fertilizing of the plants. In some cases, fertilization is secured by a natural process within the organism itself; in other cases, the pollen is scattered over a region by the wind; but the most wonderful, and at the same time efficient mode of providing for the growth of vigorous plants, is fertilization by the agency of insect life.

A brief outline of the ordinary structure of the flower will introduce to a ready appreciation of the scientific interest attaching to this last mode of fertilization, both as concerning the functions of different portions of the flowers, and the relation of dependence established between higher and lower forms of organism, so that each is dependent on the other.

Every flower as it unfolds from the bud, consists of a series of whorls, or layers of substance twined or twirled round in such a manner as to unfold or coil back, as the flower opens. The outermost of these whorls (calyx)

is a mere covering or sheath, usually of a green color, which protects the bud during the more tender period, curling up and withering as the flower opens, spreading forth its beauty. The second whorl (corolla) is what we more commonly regard as the flower proper, the colored leaves, or cup, or bell, according to the specific shape distinguishing the plant. The third whorl consists of a series of stalks or filaments (stamens) which as the flower matures or ripens stand up distinct from each other, each one having at its summit a little tuft or cushion (anther) covered with a fine dust or powder (pollen). The fourth or innermost whorl, the centre piece of the flower (pistil) is that in which the seed is generated and brought to maturity. We may thus say of the flower, that its outermost whorl is a temporary covering which withers and shrinks out of view, when the beauty of the inner structure is laid open; that the second is that which attracts the eye by the loveliness of its hues; while the two which belong to the internal structure of the flower are concerned with the reproduction or propagation of the plant, providing for the healthy germ from which a fresh plant of the same order may