11. It is with the view of contributing to the common stock of new and interesting information on this all-important question, that I bring forth the result of my inquiries into the morbid state of the human Ovum, and its structure under circumstances of premature expulsion. If such inquiries have led me to adopt the improved notions of the more modern physiologists and anatomists in these matters (which I have professedly studied, and have had the most ample opportunities of studying for many years); they have, likewise, enabled me to detect some of the oversights of those observers, and to add a little to what has already been brought forward; while, at the same time, they have induced me to join that class of writers who dismiss, as inconsistent with facts, the theories and assumptions of olden times, whose strongest authority has been their mere repetition. 12. The ideas which are now entertained respecting fecundation, after the successful congress of the two sexes, in the human species—respecting its seat—respecting the first origin, station, and rudimental creation of the embryo—respecting the journey of the latter into the womb, its sojourn in that cavity, and the various metamorphoses it undergoes therein, up to the period fixed for its projection into the WORLD, may be comprised within a small number of propositions. I shall support those propositions by references to facts, or the quotations of competent authorities, and the allegation of anatomical discoveries. But as the object of the present work is to illustrate abortion, and not the complete life-circle of the fœtus, I shall stop the number of my propositions at the _fifth_ month of its intro-uterine existence. After that period, the various phenomena of fœtal gestation are so uniform, that they afford less matter of interest to the philosopher. 13. CONCEPTION, or that result which follows sexual congress, in virtue of which one, or more individuals, of the same species is called into being, takes place in the ovarium of women. This is doubted by Meckel and others, who look upon all cases of ovaric gestation (see Plates IX. and X, A. and B.) as mere accidents, and as only proving that if conception has not before taken place in the womb, it _may_ take place in some other part connected with it; but the point has been set at rest by the more recent experiments and microscopical observations of Professor BOER, of Kœnigsberg. I adopt his conclusions. Their correctness is corroborated by the interesting experiments of Prevost and Dumas, although these experimenters admit not that fecundation takes place in the ovarium. 14. The intended receptacle of the embryo is the OVULUM. An ovulum exists in all the vesicles of Graaf, which the ovarium of a woman, who has reached maturity, contains.