Annulate lamellae in hamster pineal gland.

Pineal glands from young adult hamsters (Mesocricetus auratus Water-house) kept on a 14-10 light-dark photoperiod contain annulate lamellae. These annulate lamellae are apparently limited to the light pinealocytes. They are found in close proximity to nuclei, the Golgi apparatus, and agranular endoplasmic reticulum. There is also an interesting association or microtubules with the annulate lamellae. It seems reasonable that the presence of annulate lainellae in the pinealocytes may have some correlation with the physiological function or functions of these cells.