The body of a dead infant is found, and the physician may be called upon to answer the following questions, one or all:—Was the child mature? Was it born alive? If so, what was the cause of its death? _Was the child mature?_ Among the various signs of fœtal maturity, such as the firm, tense skin, of the usual pale corpse-color, the hair upon the head, the weight and length of the body, the diameters of the head, shoulders and hips, the horny nails reaching to the tips of the fingers, the absence of the pupillary membrane, etc., the most infallible, is the presence of the centre of ossification of the inferior femoral epiphysis. “The easiest way to find this, is to make a horizontal incision through the skin and superficial tissues over the knee-joint down to the cartilages. The patella is then to be removed, and the end of the femur made to protrude through the incision. Thin horizontal sections are then to be removed from the cartilaginous epiphysis, at first more boldly, but so soon as a colored point is observed in the last section, then very carefully, layer by layer, till the greatest diameter of the osseous nucleus is attained. This appears to the naked eye as a more or less circular bright blood-red spot in the midst of the milk white cartilage, in which vascular convolutions can be distinctly recognized.” When there is no visible trace of this centre of ossification, the fœtus can be no more than from thirty-six to thirty-seven weeks old. In still-born children, the commencement of this nucleus indicates a fœtal age of thirty-seven to thirty-eight weeks; when it possesses a diameter of from three-quarters to three lines, it shows the fœtus must have attained a uterine age of forty weeks. When the osseous nucleus measures more than three lines, we may conclude that the child has lived after birth. Isolated exceptions are occasionally met with, when, however, concomitant appearances, such as, in the one case, defective ossification of the skull, or in the other, peculiarly advanced development, will guard us against mistakes. _Was the child born alive?_ or, _Did it live during and after its birth?_ and, _If so, how long?_ These questions are intimately connected, and in order to be able to answer them, we must in our examination note the following points: