that many organisms, such as the lower colonies of protoplasmic forms, or even the mere primitive sponges themselves, remain permanently in a colonial condition, which would naturally enough represent permanent arrest of development in the early stages of egg-development; and thirdly, we learn that arrest of development, even at a later stage, may produce the colonial organisations of higher types. This latter view meets the case of the tapeworms and of the true worms likewise. In the latter, as represented by the Naïs (Fig. 10), we see the hereditary tendency towards colony-making reproduced as accurately in the buddings of new individuals from the parent-body, as in the perpetual budding of the zoophyte. Last of all, we see in the highest animals the same innate and fundamental constitution on the basis of the colony. The human frame, morphologically viewed, is a collection of cell-colonies, produced by segregation of more primitive collections of units, and primarily, if the story told by development be true, by the modification first of one cell, and secondly of one original series of cells.

The fundamental constitution of the living worlds thus appears to be of colonial nature. It remains for us to discover how the compound constitution has merged into these united and single personalities we regard as the highest members of the animal and plant series—in a word, how the "colony" has become the "individual," the highest type of which we recognise in ourselves. If varying conditions have operated to produce the diverse constitutions of animals and plants we see displayed before our waiting eyes to-day, we may justly assume that a more complex series of causes than we are able to determine is responsible for the origin of those higher natures of which we ourselves form part. Yet here and there clues to the understanding of the problem are not wanting in the considerations which the study of even lower grades of life disclose to view. The apparently single nature of the germ from which high and low organisms alike spring may best be explained, perhaps, on grounds connected with the husbanding of vital power, and on the idea that the apparent unity and singleness of the germ naturally reproduce the constitution of the single cells or units of the compound organism from which they spring. The egg or germ, in a word, reflects in its first stage the constitution of the particular unit from which it was derived. In its secondary stage it repeats the colonial condition of which its parent-unit formed part, and the features of which it is destined in due time to reproduce.

As, however, we survey the fields of animal and plant existence, we discover plainly-marked tendencies of development which fully account for the advance from the true colonial constitution of zoophyte tapeworm and social insect to the marked and apparently single personality of higher life. The higher we rise in the organic series, the less marked becomes the tendency to devote the energies of life to the perpetuation of the species or race; and the more perfectly do the powers which concentrate, ennoble, and advance the individual interests become developed. It is a self-evident fact that in lower life much of the bodily energy is occupied with the development of new individuals, or, in the case of an animal colony, with increase of the colonial membership. One has but to glance at the zoophyte-races to find clear proof of this latter statement. Imitating the plant-creation in the fulness of their vegetable growth, the tribes of zoophytes-and the tapeworm-race with its millions of ova, and indefinite reproductive power as well-unquestionably possess as their chief end the perpetuation of the race. How changed is the physiological prospect in higher existence! There the energies are devoted to the improvement, sustenance, and development of the individual. There is less devotion to the species as compared with what obtains in lower forms; and the colonial interests, whilst still represented and conserved, are limited in their scope and direction to the development of new tissue-matter. The higher animal, in short, is not obviously "colonial" in the sense that a zoophyte or a sea-mat" is compound, because the energies and forces, as well as the material, which in the lower being reproduces readily the form of the organism, are devoted to other functions. Life in the lower and compound organism is made up of one common interest, namely, the increase of the colony and species: in the higher animal, life becomes a far more personal matter, and its aims are more distinctly individualised. Existence in the colonial zoophyte is passed, so to speak, in marriage and giving in marriage; and the interests of the race are bound up in the work of its own extension. In the higher organism, individual interests and the life of the single organism occupy the greater part of its energies, so that, to use an expressive dictum, "the organism is like a society in which everyone is so engrossed by his special business, that he has neither time nor inclination to marry."

There is abundant illustration at hand of the view that the cultivation of individual interests destroys, by concentration of energy, the colonial organisation. Such an opinion finds its confirmation in the details of higher animal existence, and in the disappearance of

those powers of bodily separation after injury which characterise lower life. The organic republic or colony, in which every unit is as good as its neighbour, is typically and perfectly represented in the zoophyte. But this thoroughgoing republicanism is as impossible of continuance in higher physical existence and in spheres biological, as it is found to be incompatible with the political development of nations. That is to say, as, in the life political, here and there special developments cause men to shoot ahead of their neighbours and to distance their competitors in the struggle for existence by individual strength and excellence, so in the life biological there is the same tendency to development of individual facul

ties and powers over the common interests, and the same conversion of the colonial organisation into the concentrated structure and functions of the individual organism. In the plant-world there is a similar tendency towards concentration as the concomitant of higher life. The colonial nature of many of the lowest plants (e.g. Volvox), which consist of aggregated masses of protoplasm,is undoubted. But in the highest plant-life also (Fig. 15, 1), the colonial nature is far more strongly marked than in many animals of by no means the highest grade. Where the leaf-type (e e) repeats itself indefinitely, where bud resembles bud, where there is witnessed the gradual transformation of leaf-type into flower-type (h), and of flower into the full fruition of plant-life, there is presented to our mental view an exact picture of the budding zoophyte (Fig. 15, 2), with its series of similar units (e e)-here and there modified, now for this function, now for that; and ultimately exhibiting the closest parallelism with the plant, in that its reproductive bodies (f) are but modifications of the ordinary members of the colony; as the flower, in turn, is but the last term in the modification of the leaf. Thus, as Asa Gray well puts it, "In the ascending gradation of the vegetable kingdom, individuality is, so to say, striven after, but never obtained; in the lower animals, it is striven after with greater though incomplete success; it is realised only in animals of so high a rank that vegetative multiplication or offshoots are out of the question-where all parts are strictly members and nothing else, and all subordinated to

a common nervous centre; it is fully realised only in a conscious

derive their name from the fact that each flower of the order is not a single flower, but a collection of florets. A thistle (Fig. 21) or a daisy-head (Fig. 17 and 18), for example, is not one flower, in the sense in which a buttercup or lily is single, but is an aggregation of small stalkless flowers (18, co, co) closely packed together on one main stalk. If we examine the thistle-head, we shall find it to consist of numerous little flowers (21 c, c), of similar appearance, each containing the essential organs and parts seen in other single flowers. In the Centauries of our waysides and cornfields, we witness the same composite structure of the flower-head; but here, the outermost florets (200) of the "head" have begun to develope into petal-like organs, and have lost their stamens and pistils. The Centaury, in other words, has developed the beginning of a low individuality; it is losing its completely compound nature, and is advancing towards the singleness of type of ordinary flowers. Thus, in Centaurea nigra, these outer florets vary in size; they may resemble the inner ones in size, or may be larger, and they may want both stamens and pistils. In another species (C. scabiosa), stamens and

b, Ripe flower-head.

a

pistils never occur in the outer florets; and in Centaurea cyanus (Fig. 20) likewise, these florets (a) are useless for reproduction, and are passing towards the type and function of ordinary petals. So also in the familiar dandelions (Fig. 19), we may witness a stage in advance of the thistle. For whilst the latter plant has its florets similar and inconspicuous, the dandelion (Fig. 19) has added to its similar florets the bright corollas, which serve to render this wayside plant so conspicuous to insect eyes as well as to our own perception. When the dandelion appears with its outer florets expanded, while the inner florets have still to unfold, the flower bears no inconsiderable resemblance to the ordinary type of single flower. Far more advanced, however, towards the individuality of other plants, are the marigolds, daisies (Figs. 17, 18), and their allies. Here the likeness of the single flower deceives the nonbotanical observer into supposing that each daisy in reality corresponds to each buttercup or primrose in its constitution.

For

the outer florets of the daisy and marigold have developed, as those of the centauries.

FIG. 20.

Centaurea Cyanus, or CORN BLUEBOTTLE.

(Fig. 20, a) are developing, into long petal-like organs (Fig. 18, r). Moreover, these outer florets are losing the reproductive organs they still possess in the dandelion. The stamens have disappeared in the outer white and yellow flowers of the daisy and marigolds respectively, leaving the pistil alone represented (Fig. 18 r, sg); whilst the yellow central florets (d1 d2) possess both stamens and pistil, and are therefore the true producers of seed. It is foreign

FLORETS.

to our present inquiry to notice FIG. 21. HEAD OF THISTLE SHOWING NUMEROUS how this arrangement of the

flower parts, by placing the brightly coloured parts on the outside, imparts to these plants their conspicuous nature, and thus, by attracting