First, then, the Ovularian and Spermatic theories fail to account for the production of twins of different sexes, and for the undoubted fact of inheritance of qualities and features from both parents in varying degrees, as well as of qualities from the parent of the opposite sex.

In the next place, the theories which refer sex. to the time of impregnation fail to explain the existence of families almost exclusively of one sex, and the fact of both sexes being constantly found in the same litter of animals.

The Physical Vigour and Relative Age theory seems to explain a great deal, but contradicts itself when applied to experimental results.

Finally, the Genital Vigour theory is contradicted by the approximate balance of the sexes in the world, and fails to account for sex in the case of the lower animals, such as fish, mollusca, etc., where the question of passion cannot apply.

Any new theory to be accepted must therefore meet all these difficulties, and at the same time account for the preponderance of male births in Europe, of females among mulattoes and other hybrid races, as also among polygamous animals; and for the equality of the sexes among other animals. More especially it must suggest some principle of selfadjustment, by which not only is the balance of the sexes nearly preserved on the whole, but by which also, in cases of special disturbance, the balance tends naturally to readjust itself.

1

CHAPTER IV.

THE NATURE OF SEX AND SEXUAL EQUALITY.

Male and female the exception rather than the rule in nature-Both plants and animals afford evidence of this-As also do fishes-Each sex the equivalent of the other-Special organs met with in the higher forms of life-Division of function is the origin of sex-The propagation of trees and insects-Heterogenesis and parthenogenesis amongst moths, polyps, and bees-Alternate generation-Traditions of a bisexual progenitor in heathen mythology-The human embryo -The relative importance of the sexes-] -Man generally considered physically superior-Woman only an undeveloped man-The development of women arrested by procreative functions-Female plants less highly developed than male - Development antagonistic to reproduction-Man's susceptibility to disturbing causes-Contradictory opinions on the original sex of the embryo-Arguments in favour of female superiority-Females live longer than males, and are less liable to disease-The female amongst animals generally superior-Law of equilibrium as regards sex-The sexes throughout creation true equivalents-Plato of this opinion-Can the sexes be equalized numerically by natural selection ?-Darwin's hesitation on the point-Fertility may be hereditary, but not the production of a certain sex-No equilibrium possible in such a case-Genealogical records contradict the theory.

BEFORE enlarging upon the question of sex at

will, it is indispensable to consider the signifiance and, if possible, the origin of the sexes, and their comparative equality.

The existence of separate individuals in whom the two elements necessary to reproduction are fixed, and whose union is therefore necessary before fertilization can take place, is rather the exception than the rule throughout nature.

Professor Huxley, in treating of Biology, says:
Sustentative, generative, and correlative functions

in the lower forms of life are exerted indifferently, or nearly so, by all parts of the protoplasmic body. Generation by fission and gemmation are not confined to the simplest forms of life. Both modes are common, not only among plants, but among animals of considerable complexity. Throughout almost the whole series of living beings we find agamogenesis, or non-sexual generation. The phenomena which living things present have no parallel in the mineral world."

In the vegetable kingdom, the male and female organs are situated usually in the same flower. On rarer occasions it is found that some flowers are strictly male and others female, but even then both flowers commonly occur on the same plant, and it is only very rarely that exclusively male and female plants are met with.

Among animals, all the lowest forms, and many of the higher, including sometimes even fishes, are propagated asexually. Here, therefore, as in the vegetable kingdom, there can be no question as to the superiority of one or the other sex; each part of the organism shares in the strength or weakness of the whole.

But as the development of life is traced to higher forms, the functions are gradually specialised, i.e., special organs are set apart for the performance of special functions; such as those of prehension, digestion, respiration, locomotion, and, in some cases, reproduction. Instead of generation by simple fission, or germination from any part of the body indifferently, special organs of reproduction are appointed and fitted for exercising this function, and for nothing else.

The division into male and female organs is a later and higher stage; and the separation of these, and the lodging of them in different individuals, is a later and higher stage still. Division of function, then, is the origin of sex.

In a recent work entitled "Sexes throughout Nature," a view is put forth which may not be altogether unreasonable: "The first rise of a division of function must be everywhere accompanied by a corresponding evolution of organs; yet the formation of differentiated structure is always expensive and to be avoided except for some sufficient reason. Sexless offspring, sent out at less cost to the parent, can thrive and multiply with equal advantage to themselves, so long as there is abundant food and warmth; but with any disturbance of the equilibrium, provident Nature, alarmed for the result, begins at once to circumvent the evil by a division of the reproductive process; the result is a brood with more erfect endowments, which can continue the reproduction of the race, either asexually or sexually.

"The methods are various when the ends to be attained are the same; but apparently among all hose beings that have the two modes of propagation, ny disturbance of equilibrium, from whatever cause, produces an immediate resort to the more expensive, tut at the same time the higher and more effective process of sexual genesis. Thus a tree may be made to produce seed by under-feeding or by over-feeding, y various modes of disturbing the roots, or by prunng the branches, or merely the leaves, or by slightly girdling the bark. Unsettle the even balance in any Tay, and, in instant alarm, all the resources of the

community are turned to the propagation of a young colony which can be sent off to continue the race elsewhere.

"The instinct of the bee teaches the same lesson. The semi-sexless members of the community can be developed at less cost of nutriment, and their division of work can be performed to advantage if there is a development of no conflicting interests; but with the death of the queen, the community is unbalanced, and is in danger of destruction. Some of the young that would have remained rudimentary in sex to the end but for this derangement of function in the body politic, are immediately matured into complete young queens a process readily accomplished by giving them a generous and more stimulating diet, and a royal cell in which there is room enough to allow of the necessary growth and development. No one can fail to see the analogy between this process and the development of a leaf-bud into a flower. The annual autumnal destruction of the now useless drones is but a curious modification of similar vegetable economy seen in the annual fall of the leaf."

In the animal creation we have examples of heterogenesis (variable generation), and parthenogenesis (virgin generation). In insect life the moth generates larvæ, and these in turn become moths. The polyps, or coral-producing family, form communities and produce their offspring from themselves like the buds and ramifications of a tree; each species has its own way of branching, as much as different trees have theirs. With bees, the queens and workers are comparatively independent; the queen producing