Years of Life. 1-2. Symphysis of lower jaw. 2. Frontal suture; unites from below upwards; it may persist. Anterior fontanelle filled up. 7-8. Rami of ischium and pubes. 17. Epiphyses of upper end of ulna; small trochanter (femur). 17-18. Epiphyses of condyles (humerus); upper end of radius. 18. Epiphyses of great trochanter of femur; lower end of tibia; lower sacral vertebræ; portions of acetabulum united. 19. Epiphyses of the head of the femur. 20. Epiphyses of the head of the humerus; lower end of radius and ulna. 21. Epiphyses of the upper end of tibia; lower end of fibula. 24. Epiphyses of upper end of fibula. 25. Second and third pieces of sternum; first and second sacral vertebræ; epiphyses of clavicle, lower end of femur. 40. Manubrium, with body of sternum. Table showing the Development of the Embryo according to the Lunar Months ----------+----------+------------+---------------------------------- Month. | Length. | Weight. | Observations. ----------+----------+------------+---------------------------------- _First_. | | | (3rd or | Four to | Twenty |The embryo is curved; the mouth on 4th week.)|six lines.| grains. |the cephalic extremity appears as | | |a cleft, and the eyes as two | | |black points. Nipple-like | | |protuberances mark the position of | | |the extremities. The heart can be | | |seen, and the liver is | | |disproportionably large. ----------+----------+------------+---------------------------------- _Second_. | | | (End of |Fifteen to| Two to |The head disproportionably large. 8th week.)| eighteen | five |Nose, lips, and external parts of | lines. | drachms. |generation visible, but sex | | |doubtful. Anus appears as a dark | | |point. Abdomen encloses the | | |internal organs. Extremities | | |project slightly from the trunk. | | |_Ossification_ in _clavicle_ and | | |_lower jaw_ about end of_ seventh | | |week_; in _frontal bone_ and | | |_ribs_ towards end of _eighth | | |week_. ----------+----------+------------+---------------------------------- _Third_. | | | (End of | Two to |One to two |Eyes and mouth closed. Fingers well