Fruits of Philosophy: A Treatise on the Population Question

by Charles Knowlton

* The opinion that the spermatozoa of seminal filaments are
real animalculæ is now abandoned, but it is held by Dr.
Carpenter and other authorities that they actually, as here
stated, penetrate into the interior of the ovum. "The nature
of impregnation," says Dr. Hermann, "is as yet unknown. In
all probability it is, above all, essential, in order that
it should occur, that one or more spermatozoa should
penetrate the ovum. At any rate, spermatozoa have been found
within the fecundated eggs of the most diverse species of
animals."—Elements of "Human Physiology," translated from
the 5th ed., by Dr. Gamgee, p. 534, 1875.—G. R.

The idea that a seminal animalcule enters an ovum while it remains in the ovary, was never before advanced to my knowledge; hence I consider it incumbent upon me to advance some reason for the opinion.

First, it is admitted on all hands that the seminal animalculæ are essential to impregnation, since "they cannot be detected when either from age or disease the animal is rendered sterile."

Second, the ovum is impregnated while it remains in the ovary. True, those who never met with Dr. Dewees' theory, and who, consequently, have adopted the idea that the semen is ejected into the uterus, as the least improbable of any with which they were acquainted, have found it very difficult to dispose of the fact that the ovum is impregnated in the ovary, and have consequently presumed this is not generally the case. They admit it is certainly so sometimes, and that it is difficult to reject the conclusion that it is always so. Dr. Bostock—who, doubtless, had not met with Dewees' theory at the time he wrote, and who admits it impossible to conceive how the semen can find its way along the Fallopian tubes, how it can find its way toward the ovary, farther, at most, than into the uterus, and, consequently, cannot see how the ovum can be impregnated into the ovary—says, "Perhaps the most rational supposition may be that the ovum is transmitted to the uterus in the unimpregnated state; but there are certain facts which seem almost incompatible with this idea, especially the cases which not infrequently occur of perfect foetuses having been found in the tubes, or where they escaped them into the cavity of the abdomen. Hence it is demonstrated the ovum is occasionally impregnated in the tubes (why did he not say ovaria?), and we can scarcely resist the conclusion that it must always be the case."..."Haller discusses this hypothesis (Bostock's 'most natural supposition, perhaps') and decides against it."..."The experiments of Cruikshank, which were very numerous, and appear to have been made with the requisite degree of skill and correctness, led to the conclusion that the rudiment of the young animal is perfected in the ovarium."... "A case is detailed by Dr. Granville, of a foetus which appears to have been lodged in the body of the ovarium itself, and is considered by its author as a proof that conception always takes place in this organ."

The above quotations are from the third volume of Bostock's Physiology.

Now, as the seminal animalculæ are essential to impregnation, and as the ovum is impregnated in the ovarium, what more probable conjecture can we form than that an animalcule, as the real proper rudiment of the foetus, enters the ovum, where, being surrounded with albuminous fluid with which it is nourished, it gradually becomes developed? It may be noticed that Leeuwenhoek estimates that ten thousand animalculæ of the human semen may exist in a space not larger than a grain of sand. There can, therefore, be no difficulty in admitting that they may find their way along exceedingly minute vessels from the vagina, not only to, but into the ovum while situated in the ovarium.

I think no one can be disposed to maintain that the animalculæ merely reaches the surface of the ovum and thus impregnates it. But possibly some may contend that its sole office is to stimulate the ovum, and in this way set going that train of actions which are essential to impregnation. But there is no evidence in favor of this last idea, and certainly it does not so well harmonize with the fact that the offspring generally partakes more or less of the character of its male parent. As Dr. Dewees says of the doctrine of sympathy, "It makes no provision for the formation of mules; for the peculiarities of and likeness of parents; and for the propagation of predisposition to disease from parent to child; for the production of mulattoes," etc.

Considering it important to do away with the popular and mischievous error that the semen must enter the uterus to effect impregnation, I shall, in addition to what has been already advanced, here notice the experiments of Dr. Haighton. He divided the Fallopian tubes in numerous instances, and that after the operation a foetus is never produced, but that corpora lutea were formed. The obvious conclusions from these facts are that the semen does not traverse the Fallopian tubes to reach the ovaria; yet, that the ovum becomes impregnated while in the ovarium and, consequently, that the semen reaches the ovum in some way, except by the uterus and Fallopian tubes. I may remark, however, that a corpus luteum is not positive proof that impregnation at some time or other has taken place; yet they are so rarely found in virgins that they were regarded as such proofs until the time of Blumenbach, a writer of the present century.*

* A corpus luteum is a little yellowish body, formed in
the ovary by changes that take place in the Graafian vesicle
after it has burst and discharged its contents. Corpora
lutea were formerly considered a sure sign of impregnation,
as they were thought to be developed only or chiefly in
cases of pregnancy, but it is now known that they occur in
all cases where a vesicle has been ruptured and an ovum
discharged; though they attain a larger, size and are longer
visible in the ovary when pregnancy takes place than when it
does not.—G. R.

"Harvey and DeGraaf dissected animals at most every period after coition for the express purpose of discovering the semen, but were never able to detect the smallest vestige of it in the uterus in any one instance."—Dewells Essay on Superfoetation. The fact of superfoetation furnishes a very strong argument against the idea that the semen enters the uterus in impregnation.