It must be carefully remembered however, that these presumptive signs are precisely those most likely to be produced by other causes, particularly by _marriage only_; they must therefore be well weighed, and unless very numerous, or very distinctly marked, must not be regarded as conclusive. As already remarked, it is only during _the first three months_ that most of these presumptive signs are taken much notice of; after that we have others that can be more depended upon, and which will be described in the succeeding articles. PROBABLE SIGNS. _End of the third month._--The probable signs now to be described are seldom recognized before this time, and not generally with distinctness till a still later period. They chiefly consist of certain changes in the form, development, and position of different parts of the uterus, to ascertain which requires an internal examination. These changes are not observable till the end of the third month, previous to which time we cannot be certain that the womb has really increased beyond its normal size. And even then, when the increase is obvious, we cannot tell how it has been produced; it is not till a much later period, till five or six, or even seven months are elapsed, that pregnancy can be ascertained with anything like certainty. The changes to be noticed are in the form, and size, of the neck and body of the womb, and in its mouth, and also in the weight of the whole organ. No one, of course, can expect to recognize these changes who is not acquainted with the parts in the unimpregnated state, both in the virgin and in those who have borne children. The mode of conducting the requisite examination is, by introducing the index finger of the right hand, covered with oil or mucilage, into the Vagina, and then carrying it upwards till it reaches the Os Tincæ. By means of this finger the position and length of the neck of the womb are ascertained, and also the state of its mouth, whether it is opened or closed, and to what extent. If it be then placed at the top of the neck, on the under side, and the other hand upon the fundus of the womb externally, and pressing firmly upon it, the organ is enclosed as it were between the two hands, so that its size and form may be pretty accurately ascertained, and also its degree of firmness, by which a judgment may be formed as to whether it is occupied by any solid body, or fluid, or whether it is empty. In addition to this a pretty accurate estimate may be made of its comparative _weight_, by _balancing_, and raising it up on the finger. This is called by the French _Ballotment_, and, as will be shown further on, is a valuable means, at certain stages, of ascertaining pregnancy.--(See Plate XVI.)