Fruits of Philosophy: A Treatise on the Population Question

by Charles Knowlton

* See Dr. Carpenter's "Animal Physiology," p. 558 (published
by H. G. Bonn); Nichol's "Human Physiology," pp. 253-255
(published by Trubner & Co.)—Publishers' note.

Leeuwenhoek believed them to be the beginnings of future animals—that they are of different sexes, upon which depends the future sex of the foetus. Be this as it may, it appears to be admitted on all hands that the animalculæ are present in the semen of the various species of male animals, and that they cannot be detected when either from age or disease the animals are rendered sterile. "Hence," says Bostock, "we can scarcely refuse our assent to the position that these animalculæ are in some way or other instrumental to the production of the foetus." The secretion of the semen commences at the age of puberty. Before this period the testicles secrete a viscid, transparent fluid, which has never been analyzed, but which is doubtless essentially different from semen. The revolution which the whole economy undergoes at this period, such as the tone of the voice, and development of hairs, the beard, the increase of the muscles and bones, etc., is intimately connected with the testicles and the secretion of this fluid.* "Eunuchs preserve the same form as in childhood; their voice is effeminate, they have no beard, their disposition is timid; and finally their physical and moral character very nearly resembles that of females. Nevertheless, many of them take delight in venereal intercourse, and give themselves up with ardor to a connection which must always prove unfruitful."**

* Nichol's "Human Physiology," pp. 256-257.
—Publishers' note
** Magendic's Physiology.—Author's note.

The part performed by the female in the reproduction of the species is far more complicated than that performed by the male. It consists, in the first instance, in providing a substance which, in connection with the male secretion, is to constitute the foetus; in furnishing a suitable situation in which the foetus may be developed; in affording due nourishment for its growth; in bringing it forth, and afterward furnishing it with food especially adapted to the digestive organs of the young animal. Some parts of this process are not well understood, and such variety of hypotheses have been proposed to explain them that Drelincourt, who lived in the latter part of the seventeenth century, is said to have collected two hundred and sixty hypotheses of generation.

It ought to be known that women have conceived when the semen was merely applied to the parts anterior to the hymen, as the internal surface of the external lips, the nymphæ, etc. This is proved by the fact that several cases of pregnancy have occurred when the hymen was entire. The fact need not surprise us, for, agreeable to the theory of absorption, we have to account for it only to suppose that some of the absorbent vessels are situated anterior to the hymen—a supposition by no means unreasonable.

There are two peculiarities of the human species respecting conception which I will notice. First, unlike other animals they are liable, and for what has been proved to the contrary, equally liable—to conceive at all seasons of the year. Second, a woman rarely, if ever, conceives until after having several sexual connections; nor does one connection in fifty cause conception in the matrimonial state, where the husband and wife live together uninterruptedly. Public women rarely conceive, owing probably to a weakened state of the genital system, induced by too frequent and promiscuous intercourse.

It is universally agreed, that some time after a fruitful connection, a vesicle (two in case of twins) of one or the other ovary becomes so enlarged that it bursts forth from the ovary and takes the name of ovum, which is taken up, or rather received, as it bursts forth, by the fimbriated extremity of the Fallopian tube, and is then conducted along the tube into the uterus, to the inner surface of which it attaches itself.*

* Since Dr. Knowlton's work was written, the very important
fact has been discovered that ova are periodically
discharged from the ovaries in the human female and other
animals, not in consequence of fruitful connection having
taken place, as was formerly believed, but quite
independently of intercourse with the male. Such a discharge
of ova occurs in the lower animals at the time of heat or
rut, and in women during menstruation. At each menstrual
period, a Graafian vesicle becomes enlarged, bursts, and
lets the ovum which it contains escape into the Fallopian
tube, along which it passes to the uterus. "It has long been
known," says Dr. Kirke, "that in the so-called oviparous
animals, the separation of ova from the ovary may take place
independently of impregnation by the male, or even of sexual
union. And it is now established that a like maturation and
discharge of ova, independently of coition, occurs in
Mammalia, the periods at which the matured ova are separated
from the ovaries and received into the Fallopian tubes being
indicated in the lower Mammalia by the phenomena of heat or rut; in the human female by the phenomena of
menstruation. Sexual desire manifests itself in the human
female to a greater degree at these periods, and in the
female of mammiferous animals at no other time. If the union
of the sexes takes place, the ovum may be fecundated, and if
no union occur, it perishes. From what has been said it may
therefore be concluded that the two states, heat and
menstruation, are analogous, and that the essential
accompaniment of both is the maturation and extrusion of
ova."—"Handbook of Physiology," page 724.—G. R.

Here it becomes developed into a full grown foetus, and is brought forth about forty-two weeks from the time of conception by a process termed parturition. But one grand question is, how the semen operates itself, or any part thereof reaches the ovary, and if so, in what way it is conveyed to them. It was long the opinion that the semen was ejected into the uterus in the act of coition, and that it afterward, by some unknown means, found its way into and along the Fallopian tubes to the ovary. But there are several facts which weigh heavily against this opinion, and some that entirely forbid it. In the first place, there are several well attested instances in which impregnation took place while the hymen remained entire, where the vagina terminated in the rectum, where it was so contracted by a cicatrix as not to admit the penis. In all these cases the semen could not have been lodged anywhere near the mouth of the uterus, much less ejected into it. Secondly, it has followed a connection where from some defect in the male organs, as the urethra terminating some inches behind the end of the penis, and it is clear that the semen could not have been injected into the uterus, nor even near its mouth. Third, the neck of the unimpregnated uterus is so narrow as merely to admit a probe, and is filled with a thick tenacious fluid, which seemingly could not be forced away by any force which the male organ possesses of ejecting the semen, even if the mouth of the male urethra were in opposition with that of the uterus. But fourth, the mouth of the uterus is by no means fixed. By various causes it is made to assume various situations, and probably the mouth of the urethra rarely comes in contact with it.

Fifth. "The tenacity of the male semen is such as renders its passage through the small aperture in the neck of the uterus impossible, even by a power of force much superior to that which we may rationally suppose to reside in the male organs of generation."