Senses

Studies the senses and sense organs of animals from planarian eyes to vertebrate eyes and from bullfrog ears to insect leg hairs. Diagrams planaria's simple eyes indicating the relation of the inverted retina to the eyes of mollusks and vertebrates. Pictures the compound eyes of insects stressing their ability to measure light direction. Explains how the vertebrate eye sees, utilizing rods and cones and the breakdown of rhodopsin. Shows ear of a bullfrog and model of a human ear. Points out other ear structures and the variation in hearing sensitivities. Uses a pit viper as an example of heat sensitivity as aid to night hunting. Demonstrates, by experimental set-up, how flies can distinguish between different solutions and concentrations of the same solution and points out practical aspects of this experimentation. Views self-informing sense organs (proprioceptors) in the semicircular canals of the shark.