Abstract
Karyometric examination of [alpha]- and [beta]-cells in the islets of Langerhans in rats after starvation of up to 6 days'' duration, revealed a definite decrease in the size of the [beta]-cell nuclei which in general became more marked with increasing length of the starvation period. A less noticeable decrease in the size of the [alpha]-cell nuclei was barely, or not at all, statistically probable. No diurnal rhythm in the nuclear size was noted in the fasting rats.