Eight lectures on the signs of life from their electrical aspect eightlecturesons00wall Year: 1903 30 First or normal type. Second or transitional type. Third or reversed type. THE SIGNS OF LIFE Dark. Light. LLECT. •OOO3t O D&rk. I mm. am ins FIG. 13.—Frog's eyeball. The three types of its response to light, as described in the text.

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