Note 13 — Chapter I

The human embryo (upper fig.) is from Ecker, ‘Icones Phys.,’ 1851-1859, tab. xxx. fig. 2. This embryo was ten lines in length, so that the drawing is much magnified. The embryo of the dog is from Bischoff, ‘Entwicklungsgeschichte des Hunde-Eies,’ 1845, tab. xi. fig. 42 B. This drawing is five times magnified, the embryo being 25 days old. The internal viscera have been omitted, and the uterine appendages in both drawings removed. I was directed to these figures by Prof. Huxley, from whose work, ‘Man’s Place in Nature.’ the idea of giving them was taken. Häckel has also given analogous drawings in his ‘Schöpfungsgeschichte.’