Influence of dehydration on activity changes of pineal gland and subcommissural organ cells in Rana temporaria L. in annual cycle.

The karyometric analysis of the cells of the pineal gland and subcommissural organ in Rana temporaria L. was carried out under the influence of dehydration in the annual cycle. The dehydration stress was found to retard the activity of the pineal gland and at the same time to stimulate the activity of the subcommissural organ apart from the breeding period and the middle period of active life on land. The results showed that both the pineal gland and the subcommissural organ take part in the regulation of water balance in the species under study.