LIST OF ILLUSTRATIONS.

PORTRAIT OF ERNST HAECKEL FROM THE PAINTING BY FRANZ VON LEUBACH, 1899 (REPRODUCED BY "JUGEND").

FIGURE 1.1. THE HUMAN OVUM.
FIGURE 1.2. STEM-CELL OF AN ECHINODERM.
FIGURE 1.3. THREE EPITHELIAL CELLS.
FIGURE 1.4. FIVE SPINY OR GROOVED CELLS.
FIGURE 1.5. TEN LIVER-CELLS.
FIGURE 1.6. NINE STAR-SHAPED BONE-CELLS.
FIGURE 1.7. ELEVEN STAR-SHAPED CELLS.
FIGURE 1.8. UNFERTILISED OVUM OF AN ECHINODERM.