One may be as fully developed at six, as another at seven months. The common opinion is that the child cannot live if born before _seven months_. This, however, is incorrect. Many instances have been known of births at six months, and even earlier, in which the child lived, and became strong and healthy. Van Swieten mentions the case of one Fortunio Liceti, who was born before the sixth month. He was not larger than the hand, but grew to the average size, and lived to be seventy-one years old. Dr. Gunning Bedford mentions a similar case, in his translation of Chailly's Midwifery. There are even cases mentioned of children living at five months, but it must be borne in mind that it is seldom possible to determine the exact period. As a general rule however, the child does not live till after the seventh month, though there undoubtedly have been cases where it has lived before the end of the sixth month. The law adopts the medium period, and declares the child capable of living at _the end of the sixth month_, and not before. There is no reason whatever for supposing that it is less likely to live at eight months than at seven, or that it will not live at all at eight months, as some do. SECTION III. THE FORM, SIZE, AND POSITION OF THE FŒTUS, AND ITS APPENDAGES, AT FULL TERM. CHAPTER VIII. FORM AND SIZE OF THE FŒTUS AT FULL TERM. SIZE AND FORM OF THE BODY. The average length of the Fœtus, at full term, is about twelve inches from the head to the breech, and about eighteen inches from the head to the feet. Its weight varies from five to eight pounds, perhaps averaging about six, though some have been born weighing only three pounds, or less, and some even as high as twelve. The breadth across the shoulders is about four inches, and the same across the hips, but both are so easily compressed that during delivery they only measure about three inches, or three and a half at most. SIZE AND FORM OF THE HEAD. The head is the most important part, because it is the largest, and usually present first. It is therefore necessary to describe it fully, and with special reference to its importance, in the early stages of labor, as the part by which the position is usually determined. PLATE XXIV. The head is generally divided into the Cranium, or that part which contains the brain, and the Face. _The Bones of the Cranium._--These are seven in number, viz., two _Frontal_ Bones, or those forming the forehead; 1, 1, Figs. 1 and 2, (Plate XXIV.)--Two _Parietal_ bones, or those forming the sides of the head; 2, 2, Figs. 1 and 2.--The _Occipital_ bone, or that forming the back of the head; 3, 3, Figs. 1 and 2.--And two _Temporal_ bones, which lie over and between the ear and the eye; 4, Fig. 2. _The Bones of the Face._--These are five in number, viz., two _Superior Maxillary_, or upper jaw bones; 5, Fig. 2.--Two _Malar_, or cheek bones; 6, Fig. 2.--And one _Inferior Maxillary_, or lower jaw bone; 7, Fig. 2.