Figs. 1–8.—Development of archegonium. × 140. Fig. 9.—Sagittal section of prothallus showing first wall in fertilised ovum. × 215. Fig. 10.—Ditto, showing quadrant walls and apical cell of cotyledon. × 215. Figs. 11–13.—Ditto, showing consecutive sections (8μ) of embryo. × 215. In fig. 12 ap. cell of root is not cut medianly, cal., calyptra; cot., cotyledon; f., foot. r., root; st., stem.