by Aristotle
[It is clear also that in cases where seminal waste-products occur, they too are [25] residues. This happens when it is dissolved into what preceded it—as when plaster falls away at once from the wall; for what comes away is the same as what was at first applied. In the same way, the last residue is the same as the first wasteproduct.]22
[30] On this subject, then, so much may be laid down. But since it is necessary that the weaker animal also should have a residue greater in quantity and less concocted, and that being of such a nature it should be a mass of sanguineous liquid, and since that which has by nature a smaller portion of heat is weaker, and since it has already been stated that such is the character of the female—it is necessary that the [727a1] sanguineous matter discharged by the female is also a residue. And such is the discharge of the so-called menstrual fluid.
It is plain, then, that the menstrual discharge is a residue, and that it is analogous in females to the semen in males. The circumstances connected with them [5] are evidence that this view is correct. For the semen begins to appear in males and to be emitted at the same time of life that the menstrual flow begins in females, and that they change their voice and their breasts begin to develop. So, too, in the decline of life the generative power fails in the one sex and the menstrual discharge in the other. [10]
The following signs also indicate that this discharge in females is a residue. Generally speaking women suffer neither from haemorrhoids nor bleeding at the nose nor anything else of the sort except when the menstrual discharges are ceasing, and if anything of the kind occurs the flow is interfered with because the discharge is diverted to it. [15]
Further, the blood-vessels of women stand out less than those of men, and women are rounder and smoother because the residue which in men goes to these vessels is drained away with the menstrual discharge. We must suppose, too, that the same cause accounts for the fact that the bulk of the body is smaller in females [20] than in males among the vivipara, since this is the only class in which menstrual fluids are discharged from the body. And in this class the fact is clearest in women, for the discharge is greater in women than in the other animals. That is why her pallor and the absence of prominent blood-vessels is always most conspicuous, and the deficient development of her body compared with a man’s is obvious. [25]
Now since this is what corresponds in the female to the semen in the male, and since it is not possible that two seminal discharges should be found together, it is plain that the female does not contribute semen to the generation of the offspring. For if she had semen she would not have the menstrual fluid; but, as it is, because she has the latter she has not the former. [30]
It has been stated then that the menstrual fluids are a residue as the semen is, and confirmation of this view may be drawn from some of the phenomena of animals. For fat creatures produce less semen than lean ones, as observed before. The reason is that fat also, like semen, is a residue and is in fact concocted blood, [35] only not concocted in the same way as the semen. Thus, if the residue is consumed to form fat the semen is naturally deficient. And so among the bloodless animals the [727b1] cephalopoda and crustacea are in best condition about the time of producing eggs, for, because they are bloodless and no fat is formed in them, that which is analogous in them to fat is at that season drawn off to form the seminal residue. [5]
And a sign that the female does not emit similar semen to the male, and that the offspring is not formed by a mixture of both, as some say, is that often the female conceives without the sensation of pleasure in intercourse, and if again the pleasure is experienced by her no less than by the male and the two sexes reach their goal together, yet often no conception takes place unless the liquid of the menstrual [10] discharge is present in a right proportion. Hence the female does not produce young if the discharge is absent altogether, nor often when, it being present, the efflux still continues; but she does so after the purgation. For in the one case she has not the nutriment or material from which the foetus can be framed by the power coming [15] from the male and inherent in the semen, and in the other it is washed away with the discharge because of its abundance. But when after its occurrence the greater part has been evacuated, the remainder is formed into a foetus. Cases of conception when the discharge does not occur at all, or of conception during the discharge instead of after it, are due to the fact that in the former instance there is only so [20] much liquid to begin with as remains behind after the discharge in fertile women, and no greater quantity is secreted so as to come away from the body, while in the latter instance the mouth of the uterus closes after the discharge. When, therefore, the quantity already expelled from the body is great but the discharge still continues, only not on such a scale as to wash away the semen, then it is that [25] conception accompanies coition. Nor is it at all strange that the discharges should still continue after conception (for even after it they recur to some extent, but are scanty and do not last during all the period of gestation; this, however, is a morbid phenomenon, and that is why it is found only in a few cases and seldom, whereas it is [30] that which happens as a regular thing that is according to nature).
It is clear then that the female contributes the material for generation, and that this is in the substance of the menstrual discharges, and that they are a residue.
20 · Some think that the female contributes semen in coition because the [35] pleasure she experiences is sometimes similar to that of the male, and also is attended by a liquid discharge. But this discharge is not seminal; it is merely proper [728a1] to the part concerned in each case. For there is a discharge from the uterus which occurs in some women but not in others. It is found in those who are fair-skinned and of a feminine type generally, but not in those who are dark and of a masculine appearance. The amount of this discharge, when it occurs, is sometimes on a [5] different scale from the emission of semen and far exceeds it. Moreover, different kinds of food cause a great difference in the quantity of such discharges; for instance some pungently-flavoured foods cause them to be conspicuously increased. And as to the pleasure which accompanies coition it is due to emission not only of [10] semen, but also of a breath, the coming together of which precedes the emission. This is plain in the case of boys who are not yet able to emit semen, but are near the proper age, and of men who are impotent, for all these are capable of pleasure by rubbing. And those who have been injured in the generative organs sometimes [15] suffer from diarrhoea because the residue, which they are not able to concoct and turn into semen, is diverted into the intestine. Now a boy is like a woman in form, and the woman is as it were an impotent male, for it is through a certain incapacity that the female is female, being incapable of concocting the nutriment in its last [20] stage into semen (and this is either blood or that which is analogous to it in animals which are bloodless) owing to the coldness of her nature. As then diarrhoea is caused in the bowels by the insufficient concoction of the blood, so are caused in the blood-vessels all discharges of blood, including the menstrual blood, for this also is such a discharge, only it is natural whereas the others are morbid.
[25] Thus it is clear that it is reasonable to suppose that generation comes from this. For the menstrual blood is semen not in a pure state but in need of working up, just as in the formation of fruits the nutriment is present, when it is not yet sifted thoroughly, but needs working up to purify it. Thus the menstrual blood causes generation by mixture with the semen, as this impure nutriment in plants is [30] nutritious when mixed with pure nutriment.
And a sign that the female does not emit semen is the fact that the pleasure of intercourse is caused by touch in the same region of the female as of the male; and yet is it not from thence that this flow proceeds. Further, it is not all females that have it at all, but only the sanguinea, and not all even of these, but only those whose [35] uterus is not near the hypozoma and which do not lay eggs; it is not found in the animals which have no blood but only the analogous fluid (for what is blood in the [728b1] former is r
epresented by another fluid in the latter). The reason why neither the latter nor those sanguinea mentioned (i.e. those whose uterus is low and which do not lay eggs)23 have this effluxion is the dryness of their bodies; this allows but little [5] matter to be secreted, only enough for generation but not enough to be discharged from the body. All animals that are viviparous without producing eggs first (such are man and all quadrupeds which bend their hind-legs inwards; for all these are viviparous without producing eggs)—all these have the menstrual flow, unless they [10] are defective in development as the mule, only the efflux is not abundant as in women. Details of the facts in each animal have been given in the History of Animals.24
The menstrual flow is more abundant in women than in the other animals, and men emit the most semen in proportion to their size. The reason is that the [15] composition of their bodies is liquid and hot compared to others, for more matter must be secreted in such a case. Further, man has no such parts in his body as those to which the superfluous matter is diverted in the other animals; for he has no great quantity of hair in proportion to his body, nor outgrowths of bones, horns, and [20] teeth.
There is evidence that the semen is in the menstrual blood, for, as said before, this residue appears in the male at the same time of life as the menstrual flow in the female; this indicates that the parts destined to receive each of these residues are differentiated at the same time in both sexes; and as the neighbouring parts in both [25] become swollen the hair of puberty springs forth in both alike. As the parts in question are on the point of differentiating they are distended by the breath; this is clearer in males in the testes, but appears also about the breasts; in females it is more marked in the breasts, for it is when they have risen two fingers’ breadth that [30] the menstrual flow generally begins.
Now, in all living things in which the male and female are not separated the semen is a sort of embryo; by embryo I mean the first mixture of male and female; hence, from one semen comes one body,—for example, one stalk of wheat from one [35] grain, as one animal from one egg (for twin eggs are really two eggs). But in whatever kinds the sexes are distinguished, in these many animals may come from [729a1] one emission of semen, showing that the semen differs in its nature in plants and animals. A sign of this is that animals which can bear more than one young one at a time do so in consequence of only one coition. Hence, too, it is plain that the semen [5] does not come from the whole of the body; for neither would the different parts of the semen already be separated as soon as discharged from the same part, nor could they be separated in the uterus if they had once entered it all together; but what does happen is just what one would expect, since what the male contributes to [10] generation is the form and the efficient cause, while the female contributes the material. In fact, as in the coagulation of milk, the milk being the material, the fig-juice or rennet is that which contains the curdling principle, so acts the secretion of the male, being divided into the parts in the female. Why it is sometimes divided [15] into more or fewer parts, and sometimes not divided at all, will be the subject of another discussion. But because it does not differ in kind at any rate, several offspring are produced provided only that the divided semen is proportionate to the material, being neither too little to concoct it and fix it into form, nor too much so as to dry it up; and from this first formative semen, if it remains one, and is not divided, [20] only one young one comes into being.
That, then, the female does not contribute semen to generation, but does contribute something, and that this is the matter of the menstrual flow, or that which is analogous to it in bloodless animals, is clear from what has been said, and also from a general survey of the question. For there must needs be that which [25] generates and that from which it generates; even if these be one, still they must be distinct in form and their essence must be different; and in those animals that have these powers separate in two sexes the body and nature of the active and the passive sex must also differ. If, then, the male stands for the effective and active, and the [30] female for the passive, it follows that what the female would contribute to the semen of the male would not be semen but material for the semen to work upon. This is just what we find to be the case, for the menstrual blood has in its nature an affinity to the primitive matter.
21 · So much for the discussion of this question. At the same time the answer to the next question we have to investigate is clear from these considerations, [729b1] I mean how it is that the male contributes to generation and how it is that the semen from the male is the cause of the offspring. Does it exist in the body of the embryo as a part of it from the first, mingling with the material which comes from [5] the female? Or does the semen communicate nothing to the material body of the embryo but only to the power and movement in it? For this power is that which acts and makes, while that which is made and receives the form is the residue of the secretion in the female. Now the latter alternative appears to be the right one both a priori and in view of the facts. For, if we consider the question on general grounds, [10] we find that, whenever one thing is made from two of which one is active and the other passive, the active agent does not exist in that which is made; and, still more generally, the same applies when one thing moves and another is moved. But the female, as female, is passive, and the male, as male, is active, and the principle of the movement comes from him. Therefore, if we take the highest genera under [15] which they each fall, the one being active and motive and the other passive and moved, that one thing which is produced comes from them only in the sense in which a bed comes into being from the carpenter and the wood, or in which a ball comes into being from the wax and the form. It is plain then that it is not necessary that anything at all should come away from the male, and if anything does come away it does not follow that this gives rise to the embryo as being in the embryo, but only as that which imparts the motion and as the form; so the medical art cures the [20] patient.
This a priori argument is confirmed by the facts. For it is for this reason that some males which unite with the female do not, it appears, insert any part of themselves into the female, but on the contrary the female inserts a part of herself into the male; this occurs in some insects. For the effect produced by the semen in [25] the female is produced in the case of these insects by the heat and power in the male animal itself when the female inserts that part of herself which receives the residue. And therefore such animals remain united a long time, and when they are separated the young are produced quickly. For the union lasts until that which is analogous to [30] the semen has done its work, and when they separate the female produces the embryo quickly; for the young is imperfect inasmuch as all such creatures give birth to grubs.
What occurs in birds and oviparous fishes is the greatest proof that neither does the semen come from all parts of the male nor does he emit anything of such a [730a1] nature as to exist within that which is generated, as part of the material embryo, but that he only makes a living creature by the power which resides in the semen (as we said in the case of those insects whose females insert a part of themselves into the male). For if a hen-bird is in process of producing wind-eggs and is then trodden by the cock before the egg has begun to whiten and while it is all still yellow, then they [5] become fertile instead of being wind-eggs. And if while it is still yellow she be trodden by another cock, the whole brood of chicks turn out like the second cock. Hence some of those who are anxious to rear fine birds act thus; they change the [10] cocks for the first and second treading, not as if they thought that the semen is mingled with the egg or exists in it, or that it comes from all parts of the cock; for if it did it would have come from both cocks, so that the chick would have all its parts doubled. But it is by its force that the semen of the male gives a certain quality to the material and the nutriment in the female, for the second semen added to the [15] first can produce this effect by heat and concoction, as the egg acquires nutriment so long as it is growing.
The same thing happens in the genera
tion of oviparous fishes. When the female has laid her eggs, the male sprinkles the milt over them, and those eggs are fertilized which it reaches, but not the others; this shows that the male does not [20] contribute anything to the quantity but only to the quality of the embryo.
From what has been said it is plain that the semen does not come from the whole of the body of the male in those animals which emit it, and that the [25] contribution of the female to the generative product is not the same as that of the male, but the male contributes the principle of movement and the female the material. This is why the female does not produce offspring by herself, for she needs a principle, i.e. something to begin the movement in the embryo and to define the form it is to assume. Yet in some animals, as birds, the nature of the female [30] unassisted can generate to a certain extent, for they do form something, only it is incomplete; I mean the so-called wind-eggs.