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"In the great quadruped known as titanothere," says Osborn, "rudiments of horns first arise independently at certain definite parts of the skull; they arise at first alike in both sexes, or asexually; then they become sexual, or chiefly characteristic of males; then they rapidly evolve in the males while being arrested in development in the females; finally, they become in some of the animals dominant characteristics to which all others bend."
The child had abstracted its gaze, which was now directed down the aisle of the carriage, indefinitely focussed on some point outside the window. It seemed remote, entirely unconcerned with any human being. I speak of it asexually. I was still uncertain as to its sex.
This tendency to variation is less marked in that mode of propagation which takes place asexually; it is in that mode that the minor characters of animal and vegetable structures are most completely preserved.
The mother would probably be terrified if it were explained to her that all her tenderness awakens the sexual impulse of her child and prepares its future intensity. She considers her actions as asexually "pure" love, for she carefully avoids causing more irritation to the genitals of the child than is indispensable in caring for the body.
Asexually multiplied strains may be said to be generally two times or even three times superior to the common offspring. This is a difference of great practical importance, and should never be lost sight of in theoretical considerations of the productive capacity of selection. Multiplication by seed however, has one great advantage over the asexual method; it may be repeated.
That character which is common to these two distinct processes is this, that, whether we consider the reproduction, or perpetuation, or modification of organic beings as they take place asexually, or as they may take place sexually, in either case, I say, the offspring has a constant tendency to assume, speaking generally, the character of the parent.
In the case of asexually and sexually produced organisms alike, the offspring must be held to continue the personality of the parent or parents, and hence on the occasion of every fresh development, to be repeating something which in the person of its parent or parents it has done once, and if once, then any number of times, already.
On the other hand, Harvey's dictum, "Every living thing comes from an egg," is only true in a limited sense, namely, that whilst the individual among most larger animals and plants is always traceable to an egg-cell detached from a parental individual of a like kind of species, there are whole groups and series of lower animals and most plants in which the individual born or "developed" from an egg-cell does not proceed when grown to full size to reproduce in turn by eggs and fertilising sperms, but divides into two or more individuals or gives off detached buds or reproductive bulbs, which become separate individuals, and only after these and several successive generations of individuals have been thus produced "asexually," by fission or by budding, does a generation appear which produces true egg-cells and sperm-cells and reproduces by their means.
An impregnated egg develops into an asexual form, A; this gives rise, asexually, to a second form or forms, B, more or less different from A. B may multiply asexually again; in the simpler cases, however, it does not, but, acquiring sexual characters, produces impregnated eggs from whence A, once more, arises.
An impregnated egg develops into an asexual form, A; this gives rise, asexually, to a second form or forms, B, more or less different from A. B may multiply asexually again; in the simpler cases, however, it does not, but, acquiring sexual characters, produces impregnated eggs from whence A, once more, arises.
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