THE EFFECT OF TEMPERATURE CHANGES UPON THE PULSATIONS OF ISOLATED SCALE MELANOPHORES OFFUNDULUS HETEROCLITUS

Abstract

1. Pulsations in isolated scale melanophores of Fundulus heteroclilus occur in N/10 NaCl after treatment with N/10 BaCl₂ at any temperature between 12° and 32° C. 2. Below 12° C. pulsations cease, the melanophore coming to rest in the maximally expanded state. 3. Above 32° C. pulsations also cease, the melanophore coming to rest in the punctate state. 4. Between 12° and 32° C. the extent of the pulsations decreases in a rectilinear manner with an increase in temperature. 5. Between 12° and 27° C. the rate of pulsations increases in a non-rectilinear manner with an increase in temperature. With a further rise in temperature above 27° C. there is a rapid decrease in the rate of pulsations.