The geometric progression of nuclear volumes.

Vesicles formed by the fragmentation of biomembranes form discrete size classes. Their surface areas can be represented by two geometric series with a common ratio of 2. The surface areas of membrane vesicles found in intact cells, including nuclear envelopes are terms of the same two series. These observations can be interpreted as indicating that nuclear volumes have physically determined, discrete values, which do not vary in a continuous way. Therefore an increase of nuclear volume, for any reason, will result in a jump to the next larger term in the series.