Evening Republican, Volume 20, Number 100, Rensselaer, Jasper County, 26 April 1916 — Fishes and Frogs Show That They Know Colors [ARTICLE+ILLUSTRATION]

Fishes and Frogs Show That They Know Colors

wjjADISON WIS —That fish know the difference between colors and have a M sense of association seems to be indicated by an experiment recently made by an assistant in the zoology department of the University of Wisconsin. Mud minnows were used, and the

experiments consisted of placing colored pasteboard disks, nailed to sticks, into the aquarium just before feeding time, so that the fish could see theilfc: When a blue or yellow disk was used a luscious worm or similar delicacy was attached to the disk, but a red disk was accompanied by a lump of unedible filter paper. The fish soon learned that blue and yellow meant a meal, whereas red did not. Now when they see the dinner-bell colors

approaching they ueconie so excited that they almost jump out of the aquarium for the food. Red does not interest them at all. Frogs indicated sense of color in a similar experiment performed by another student. In their case the food was attached to the colored disk so that they had to stand upon a zinc plate to reach it. They were allowed tc take the food from blue or yellow disks, but when the disk of red was used a current of electricity was turned on to give them a mild shock. It took three trials to teach them which color to avoid. Another student found that a turtle could distinguish sound well enough to tell whether a horn or bell meant dinner.