Notwithstanding it may be thought I have dwelt too long upon this subject, I cannot conclude it without making one remark, from which some useful conclusions may be drawn. These pretended spermatic animals, which are only living organic particles of the nutriment, not only exist in the seminal liquors of the two sexes, and in the residue of the nutriment which adheres to the teeth, but also in the chyle and excrements. Leeuwenhoek having met with them in the excrements of frogs, and other animals, which he dissected, was at first very much surprised, and notable to conceive from whence these animals proceeded, so entirely like those he had observed in the seminal liquors, accuses himself of having, in dissecting the animal, opened the seminal vessels, and that the seed had by that means been mixed with the excrements. But having afterwards found them in the excrements of other animals, and even in his own, he no longer knew to what to attribute them. Leeuwenhoek, it is worthy remark, never met with them in his own excrements, but when they were liquid. Every time he was disordered and the stomach did not perform its functions, and was relaxed, he discovered these animalcules; but when the concoction of the food was well performed, and the excrement was hard, there was not a single one, although it was diluted with water. This seems perfectly to agree with all we have before advanced: for when the stomach and intestines perform their functions, the excrements are only the grosser parts of the nutriment; and all that is really nutritive and organic passes into the vessels which serve to nourish the animal; whereas if the stomach and intestines are not in a condition to comminute the food, then it passes with the inanimate parts, and we find the living organic molecules in the excrements; from whence it may be concluded, that those which are often lax must have less seminal liquor, and be less proper for generation, than those of a different habit of body.