"In cases where the generative organs are still uninjured, and the constitution healthy, seminal emissions will be only voluntary, and if the digestive powers are good we may promise a speedy reparation. But if irritation has already seized upon the spermatic organs and an abundant supply of semen escapes daily, or several times a day, without the patient's knowledge, the digestion will become deranged, and the power of erection, as well as pleasurable sensation, will diminish." (P. 472.)

TREATMENT. The same or similar treatment to that already pointed out as the best for nocturnal emissions, should be followed where the disease is still in the condition of diurnal emission merely. It is then, to a very great extent, amenable to the will and to medical treatment. When it assumes the form of spermatorrhoea, the treatment detailed hereafter under that head should be adopted. (See p. 219.)

CHAPT. III.--THE EMITTED FLUID SEMEN.

WE now come to the third of the subjects above specified; that is, the secretion itself.

PART I.

NORMAL FUNCTIONS, AND CONDITION OF THE SEMEN.

COMPOSITION OF SEMEN.-" Pure semen," says Carpenter, "is a milky fluid of a mucous consistence, and neutral, or slightly alkaline reaction. The imperfectly developed spermatozoa are composed of an albuminous substance, the quantity of which diminishes with their progress toward maturation; so that the perfectly developed semen contains no albuminous compound. On the other hand, the principal component substance of the mature spermatozoa is the same with that which is the chief constituent of the epithelia, and of the horny tissues generally; namely, the 'binoxide of protein' of Mülder. Besides this, the spermatozoa contain about four per cent. of a butter-like fat, with some phosphorus in an unoxidized state (probably combined with the fat, as in the phosphorized fats

of the blood-corpuscles and of nervous matter), and about five per cent. of phosphate of lime. The fluid portion of the secretion is a thin solution of mucus, which, in addition to the animal matter, contains chloride of sodium, and small quantities of alkaline sulphates and phosphates. The peculiar odor which the semen possesses does not appear to belong to the proper spermatic fluid, but is probably derived from one or other of the secretions with which it is mingled.

"THE MODE OF EVOLUTION of the spermatozoa is such as to indicate that these bodies are true products of the formative action of the organs in which they are found, and cannot be ranked in the same category with animalcules. They are developed in the interior of cells, or vesicles of evolution, such as are visible in the seminal fluid in various stages of production (figs. F, G, H, I), and have been known under the head of seminal granules.

A, B, C. Single vesicles of evolution, of different sizes, from the seminal fluid of the dog. D. Single vesicle, within its parent cell. E. Parent cell, inclosing seven vesicles of evolution. F, G. Vesicles containing spermatozoa in process of formation. H, I. Spermatozoa escaping from the vesicles. (Copied from Wagner and Leuckardt.)

"These appear to have been themselves formed within parent cells, which are probably to be regarded as the epithelial cells of the tubuli seminiferi, constituting, like the analogous cells of other glands, the essential elements of the spermatic apparatus. These parent cells are sometimes observed to contain but a single vesicle of evolution, as shown at D; but more commonly from three to seven are seen within them, as in E.

"When the vesicle is completely matured, it bursts, and gives

exit to the contained spermatozoa. The spermatozoa are not normally found free in the tubuli seminiferi, although they may be there so far advanced in development, that the addition of water liberates them by occasioning the rupture of their envelopes. In the rete testis and vasa deferentia the spermatozoa are very commonly found lying in bundles within the parent cells, the vesicles of evolution having disappeared; and they are usually set free completely by the time that they reach the epididymis, though still frequently associated in bundles. The earlier phases are occasionally met with, however, even in the vas deferens."

THAT THE ESSENTIAL ELEMENTS of the spermatic fluid are the spermatozoa, may be reasonably inferred from several considerations. There are some cases in which the liquor seminis is altogether absent, so that they constitute the sole element of the semen; but they are never wanting in the semen of animals capable of procreation, though they are absent, or imperfectly developed, in that of hybrids which are nearly or entirely sterile. Moreover, it may be considered as certain that the absolute contact of the spermatozoa with the ovum is requisite for its fecundation. This appears from the fact that, if the spermatozoa be carefully removed from the liquor seminis by filtration, the latter is entirely destitute of fertilizing power. Hence the presence of the liquor seminis must be considered as merely incidental, and as answering some secondary purpose either in the development or in the conveyance of the spermatozoa.

Müller says: "Not only are spermatozoa absent from the semen of many animals, and particularly of birds-except at the pairing time—but the development is imperfect in hybrid animals, which are generally incapable of reproducing their kind, or at most pair with individuals of one of the unmixed species, and produce forms which then return to the original fixed type. Hebenstreet, Bonnet, and Gleichen, all failed to detect spermatozoa in the semen of the male mule." (Vol. ii, p. 1478.)

SECRETION OF SEMEN.-Carpenter says, in his "Comparative Physiology," p. 533:

"The development of the spermatozoa is, in most cases, periodical, man and most of the domesticated races being the only animals in which there is a constant aptitude for procreation. The spermatic

1 "Human Physiology," p. 791, fifth edition.

organs, which remain for long periods in a state of atrophy, at particular times take on an increased development, and their product is then formed in great abundance.”

The secretion of semen takes place slowly in the continent man -so slowly that in fact, in many instances, I think little or none is formed in healthy adults whose attention is not directed to sexual subjects, and who take a great deal of strong exercise. The same may be said of animals that are not allowed sexual congress. QUALITY OF THE SEMEN.-Semen, as we have said (p. 164), when first secreted is not the same elaborated fluid which we find in the vesicula seminales. The development of the spermatozoa in their full numbers and vigor is not completed till the semen has reached, or has for some time lain in the vesiculæ seminales. Immediately after its first secretion, the semen contains none of these bodies, but only granules and those round corpuscles which are known as seminal corpuscles like large nuclei inclosed within parent cells. Within each of these corpuscles or nuclei, a seminal filament is developed by a similar process in nearly all animals. Each corpuscle or nucleus is filled with granular matter; this is gradually converted into a spermatozoid, which is at first coiled up, and in contact with the inner surface of the wall of the corpuscle.-Kirkes, p. 630.

In respect of these vivifying agents, the spermatozoa, the microscope shows that specimens of semen differ much; that in some persons it is, so to speak, permanently immature, and that in other instances it may be so temporarily.

IS THE SEMEN SECRETED AS REQUIRED, OR STORED UP?-On this rather doubtful point, it seems to me, after some investigation, pretty clear that the semen is stored up and elaborated in the vesiculæ seminales. It is tolerably certain that the testicles do not go on continually secreting, but cease when there is no further occasion for their action. This seems very probable from the fact that the vas deferens is generally found empty in men who have been long removed from the society of women. As the semen is secreted, I believe it is pushed forward into the vasa deferentia, and thence is deposited in the vesiculæ seminales, and, while there, mixed with the secretion of those organs. It is then ready for use at an instant's notice. It is owing, I believe, to its previous secretion, elaboration, and storing up, that under such slight mental or physical causes

emission occurs so readily. If it were not ready at a moment's call, much more excitement than that required to produce nocturnal emission would be necessary to cause ejaculation. In many animals, this storing up does not and cannot occur, there being in some no vesiculæ seminales. But in most of these cases there are means for attaining the same end-the elaboration of the semen-as, for instance, the dilatation of the vasa deferentia. Thus, "In the horse this portion of the duct is extremely thickened by the occurrence of numerous glandular cellules in its walls. Much the same condition is met with in the bull. In the elephant each vas deferens, when it arrives at this point, enlarges into a cavity of considerable size, which it is evident may readily, and no doubt does. really, fulfill the function indicated by the words vesiculæ seminales." -Pittard, "Cyclop. of Anat. and Physiol.," vol. iv, p. 1431.

But the chief difference between most animals and man, is that man has no rutting season. He may require his semen at any moment; and the vesiculæ seminales supply his need. The animal, on the contrary, requires the power of, for a short time, producing enormous quantities of semen at very short notice, which it expends as it is secreted. The periodic enlargement of the testes, and the other changes noticed at the rutting season, supply this requirement. The system answers wonderfully to these sudden demands. We see, for instance, nature called upon for sudden and extraordinary supplies of horn or bone. Bone, we know, grows very slowly under ordinary circumstances; it is often deposited round fractures in less quantities than we wish; yet such is the lavishness of nature when called upon, that a stag's antlers will be replaced fully in eleven weeks.

The injected preparations made by John Hunter of the testes of animals that have a rutting season, show how a healthy male may secrete an almost unlimited quantity of semen for a short time. Besides, the animal has two testes, only one of which probably is drained at a time, and a large quantity of semen may be hoarded up in the testes and vasa deferentia.

THE QUANTITY OF SEMEN ACTUALLY EMITTED IN EACH SEXUAL ACT IN MAN amounts, generally, to two teaspoonfuls or one, according as the male has been continent or not. Of course the whole of this emission does not consist of pure semen alone. The secretion as it leaves the meatus is a heterogeneous compound.