The sense of touch—The senses of taste and smell—Actinophryans having taste—The sense of sight—Modification of sight organs by surroundings—Sight in Actinophryans—Blind fish sensitive to light—Blind spiders—Blind man—Primitive eyes in Cymothoe—In the jelly-fish, sea-urchin, Alciope, Myrianida—The sight organs of the snail—Power of vision in the snail—Eyes of crayfishâ€â€¦