Degeneration of Melanophores in Fundulus

Abstract

The melanophores of F. heteroclitus degenerate and decrease in number if the fishes are kept for some time in white surroundings. In black surroundings no such decrease occurs. These observations seem to support the hypothesis that continued expansion of pigment cells favors an increase in their number and in the amount of pigment contained in them, while continued contraction opposes such an increase. The marked degeneration described shows that continued contraction not only checks any increase in the number of melanophores but is likely to bring about a decrease.