Somatogenic characters, [412].
Spathegaster, [49].
Spencer, Herbert, on relation of absorbing surface to size of animal, [7];
on influence of diminished nutrition, [241];
on correlation, [389].
Spirogyra, on cell-division in, [216].
Sponges, polar bodies of, [217].
Spontaneous generation, [34].
Sprengel, on colours in flowers, [308].