Abstract
The timing of the activity period of 12 adult and 2 young deer mice (Peromyscus) was studied in constant darkness. With both of the young and nine of the adults the activity began earlier each day. The rate of the shift varied between animals, being highest in one of the young (56 minutes per day); the higher rates appeared to be linear. The imposition of alternating light and dark prevented the shift, and constant light reversed it.

This publication has 0 references indexed in Scilit: