jections of the frontal sinus; nor are the epiphyses consolidated with the body of the bones, so as to constitute apophyses, until many years. With regard to the general developement of the skeleton after birth, it may be observed, that the proportion of cartilage is in an inverse ratio to the age; reckoning from the twentieth year backwards, the younger the subject the larger is its head, compared with the trunk and limbs; the smaller the bones of the face, but the larger the fontanelles; the flatter is the lower part of the face; the larger the chest, in relation to the pelvis; the shorter the limbs; the larger the clavicles; the smoother and flatter the broad bones, but the rounder those that are cylindrical. (See Albert Durer on the proportions of the bones, Lib. 1.) The chemical composition of the bones, in relation to their phosphate of lime, and gelatine, varies also very materially at different ages. It may be stated that the quantity of the former substance deposited in the texture of bones, is in the direct ratio of the age; the bones of the fœtus are at first entirely gelatinous; at the time of birth, and during the first years of life the organic part superabounds; in youth the quantity of each constituent is nearly equal; in adults the calcareous earth forms almost two-thirds of their substance; and finally, by gradual accumulation in old age, its excess obliterates the organized parts; so that the skeleton of the aged person may be distinctly recognised; besides which, the sutures of the skull are generally lost, and the absorption of the alveolar processes again imparts to the face the physiognomy of the infant.
The male and female skeleton may be said to differ, not only in the whole combination, or in the general impression, from a comparative survey, but also in
