1. The ultimate purpose of nature, in associating the two sexes in the human species, is to bring to maturity and produce, in a fit state to live and procreate, a constant succession of individuals, that shall perpetuate the species to the end of time. 2. This object is invariably accomplished by one uniform series of laws and phenomena, which have been studiously inquired into, accounted for, and, in most instances, explained in a satisfactory manner, amounting almost to demonstration. 3. The study of the function of reproduction, in all the other classes of animals, affords no other nor any dissimilar evidence. On the contrary, both by comparison and analogy, the study in question serves to confirm us in the notion, that Man differs in nought, in this respect, from the animated beings placed below him in the scale of creation. One same primary intention is manifest in their sexual distinctions; the means to ensure the ultimate purpose—their perpetuation—are the same; the same laws and the same phenomena mark the appearance, the development, and the final production of successive generations of individuals. 4. Any deviation from those laws—any violent change in those phenomena—and, still more so, any impediment to the accomplishment of the _ultimate purpose_ of Nature, is a defeat of her intention. 5. Such a deviation, change, or impediment may occur at any time previously to the period established for the appearance of a new and perfect being. If it occur at such a time as shall be incompatible with the maturation, and consequently with the life of the new creature, or even with its maturation alone, (although tokens of life be observed at the time in question,) a MISCARRIAGE is said, in common parlance, to have taken place; for Nature has _miscarried_ in her undertaking: she has been foiled in her expectations. 6. In the reproduction of the human species, such an event might justly be considered to have occurred, if, at any time before the completion of the natural period of gestation, the fœtus be expelled, whether dead or alive. But as in many instances, notwithstanding its premature expulsion, the fœtus has grown and has continued to live its extra-uterine life, in spite of the want of maturity, (a case known to have occurred even so early as between the sixth and the seventh month,) the expression, before mentioned, (5) is not applied to any untimely expulsion of the fœtus that may take place later than that period—at which, and after which, and till the completion of the ninth month of gestation, such an expulsion would be called a _premature_ labour. The distinction, however, is more specious than useful: it is an offering to social etiquette, rather than to science.