XXI. On the evolution of the Placenta, and on the possibility of employing the characters of the Placenta in the classification of the Mammalia 734 1882 XXII. On the structure and development of Lepidosteus. By F. M. BALFOUR and W. N. PARKER. With Plates 34-42 738 XXIII. On the nature of the organ in Adult Teleosteans and Ganoids which is usually regarded as the Head-kidney or Pronephros 848 XXIV. A renewed study of the germinal layers of the Chick. By F. M. BALFOUR and F. DEIGHTON. With Plates 43, 44, 45 854 POSTHUMOUS, 1883 XXV. The Anatomy and Development of Peripatus Capensis. Edited by H. N. MOSELEY and A. SEDGWICK. With Plates 46-53 871 Francis Maitland Balfour, the sixth child and third son of James Maitland Balfour of Whittinghame, East Lothian, and Lady Blanche, daughter of the second Marquis of Salisbury, was born at Edinburgh, during a temporary stay of his parents there, on the 10th November, 1851. He can hardly be said to have known his father, who died of consumption in 1856, at the early age of thirty-six, and who spent the greater part of the last two years of his life at Madeira, separated from the younger children who remained at home. He fancied at one time that he had inherited his father's constitution; and this idea seems to have spurred him on to achieve early what he had to do. But, though there was a period soon after he went to College, during which he seemed delicate, and the state of his health caused considerable anxiety to his friends, he eventually became fairly robust, and that in spite of labours which greatly taxed his strength.