156
R. LALLIER
18.50
19, W
19,30
FIG. 5. Changes in colour of Janus green showing reduction gradients in blastulae
vegetalized by lithium ions. No animal reduction gradient is present here. Mesenchyme
cells are displaced towards the animal pole. Large dots, blue ; small dots, red ; no dots, the
colour has faded. Figures indicate time of observations (from Hörstadius, 1955).
FIG. 6. Reduction gradients in isolated animal halves (from Hörstadius, 1952).
R. LALLIER
18.50
19, W
19,30
FIG. 5. Changes in colour of Janus green showing reduction gradients in blastulae
vegetalized by lithium ions. No animal reduction gradient is present here. Mesenchyme
cells are displaced towards the animal pole. Large dots, blue ; small dots, red ; no dots, the
colour has faded. Figures indicate time of observations (from Hörstadius, 1955).
FIG. 6. Reduction gradients in isolated animal halves (from Hörstadius, 1952).