XIV. I then opened a dog, and separated the testicles and the adherent vessels, but I perceived no seminal vesicles, and apparently the seed in those animals passes directly from the testicles into the urethra. I found but a small quantity of liquor in the testicles, although the dog was adult and vigorous. In the small quantity I could collect I could not discover any bodies that were in motion. I only perceived a great quantity of very small globules, most of which were motionless, and some of the smallest had some trifling approximating motion, which I could not follow, because the drops I gathered were so exceedingly minute that they dried in two or three minutes after they were placed in the microscope.
XV. Having cut the testicles of this dog into two parts, I infused it in water, and closely sealed up the vessel. Three days after I examined this infusion, which I made with the design of discovering whether the flesh did not contain moving bodies, and I saw a great quantity of moving bodies of a globular and oval form, like those I had seen in the seminal liquor of the dog, excepting they had not any threads. They moved in all manner of directions with great swiftness. I observed these bodies, which appeared animated for some time, and saw many change their form; I perceived some to lengthen, and others to contract, while some swelled at both extremities: there were numbers that were smaller and thicker than the rest; but they were all in motion, and were about the size and figure of those I have described in the fourth experiment.
XVI. The next morning the number of these globules were increased, but they appeared smaller; their motion was more rapid and irregular; they had also another appearance with respect to their form and manner of moving, which seemed confused; the next and several days after, till the fifteenth day, there were moving bodies in the water, whose size gradually diminished till they were no Longer visible. The last, which I perceived with great difficulty, was on the nineteenth and twentieth days, and they moved with greater rapidity than ever. Upon the water a kind of pellicle was formed, which appeared to be composed of the coverings of those moving bodies, small threads, scales, &c. but entirely motionless; this pellicle, and the moving bodies could not come into the liquor by means of external air, since the bottle had been kept carefully sealed.
XVII. I then successively opened ten rabbits, on different days, to examine their seminal liquors; the first had not a drop, either in the testicles or seminal vessels. In the second I was no more successful, although I was assured he was the father of a very numerous progeny. I succeeded no better in the third. I then imagined that the presence of the female might be requisite; I therefore put males and females into cages so contrived that it was impossible for them to copulate. At first these endeavours did not succeed; for, on opening two, not a drop of seminal liquor was to be found; however, in the sixth that I opened, a large white rabbit, I found, in the seminal vesicles, as much liquor as could be contained in a teaspoon; this matter resembled calves' jelly, was nearly transparent, and of a citron colour. Having examined it with the microscope, I perceived it to resolve, by slow degrees, into filaments and thick globules, many of which appeared fastened to each other; but I did not remark any distinct motion in them, only as the matter liquefied, it formed a kind of current by which these filaments and globules seemed to be drawn all to one side. I expected to find this matter take a greater degree of fluidity, but that did not happen, for, after it was a little liquefied, it dried, and I could perceive nothing further than what is above mentioned. When this matter was mixed with water, the latter did not appear to have power to dilute it.
XVIII. Having opened another rabbit, I only found a very small quantity of seminal matter, which was of a colour and consistency entirely different from the former; it was scarcely tinctured of a yellow hue, and was much more fluid. As there was but very little, I feared it would dry too hastily, and therefore mixed it with water: from the first observation, I did not perceive the filaments I had seen in the other, but I discovered three globules, all in a trembling and restless motion; they had also a progressive motion, but it was very slow; some moved round the others, and most appeared to turn upon their centres. I could not pursue this observation because the liquor so soon got dry.
XIX. I opened another of these rabbits, but could not discover any of this matter; in the seminal vessels of another, I found almost as much congealed liquor as in [XVII]th Experiment: I examined it in the same manner as the rest, but it afforded me no greater discovery. I infused the whole I had collected, in almost double the quantity of water, and after briskly shaking them together, I suffered them to settle for ten minutes; after which, on inspecting this infusion, I saw the same large globules as before; there were but few and those very distant from each other. They had approximating motions with respect to each other, but they were so slow, as to be scarcely discernable; two or three hours after, these globules seemed to be diminished, their motion was become more distinct, and they appeared to turn upon their centres. Although this trembling motion was more than their progressive, nevertheless they were clearly seen to change their situation irregularly with respect to each other. Six or seven hours after the globules were become still less, and their action was increased: they appeared to me to be in much greater numbers, and all their motions distinct. The next morning, there was a prodigious multitude of globules in motion, which were at least three times smaller than those that at first appeared. I observed these globules for eight days, and observed that many of them seemed to join together, after which their motion ceased; this union, however, appeared to me only superficial and accidental. Some were larger than others; most were round and spherical, and some of them were oval. The largest were most transparent, and the smallest were almost black. This difference did not proceed from the light, for in whatever situation these small globules were in, they were always of the same appearance; the motions of the small were much more rapid than the large ones, and what I remarked most clearly and most generally in all, was their diminution of size, so that at the eighth day they were so exceedingly small as to be hardly perceptible, and at last absolutely disappeared.
XX. At length having obtained, with no small difficulty, the seminal liquor of another rabbit, as it would have been conveyed to the female, I remarked it to be more fluid than that which had been taken from the seminal vesicles, and the phenomena which it offered were also very indifferent; for in this liquor there were moving globules and filaments without motion; and also a kind of globules with threads or tails, resembling those of a dog or a man, but only appearing smaller and brisker ([fig. 7.]) They passed over the microscope in an instant, their tails appeared shorter than those of other spermatic animals, and I own I am not certain whether some of those tails were not false appearances, produced by the furrows which these moving globules formed in the liquor, as they moved with too great a rapidity to admit of my clearly observing them; besides, the liquor, though sufficiently fluid at first, very speedily dried away.
XXI. After this I resolved to examine the seminal liquor of a ram; I applied to a butcher, who supplied me with the necessary parts of at least twelve or thirteen, directly after they were killed, but I could not find liquor sufficient for any experiment, either in the epididymis or seminal vesicles. In the little drops I was able to collect, I only perceived globules which had no motion. As I made these experiments in March, I supposed by repeating them in October, the season of female attachments, I should discover more seminal liquor in these vessels. I cut many of these testicles in two longitudinally, and collected a small quantity of liquor, but found nothing more in them.
| Fig. 7 | Fig. 8 |
| Fig. 9 | Fig. 10 |
| Fig. 11 | Fig. 12 |