The Structure of Nuclear Membrane in Larval Gonads of Heliothis obsolete.

Electron microscope studies on thin sections of germ cells of the larva Heliothis obsoleta have revealed the presence in the nuclear membrane of pore-like structures which are spaced about 1300 A apart. The pores are approximately 280 A in diameter and are surrounded by a relatively dense wall about 320 A in diameter. Thus, the diameter of the pore plus the surrounding wall is approximately 920 A. 2. The pores appear to be of a size that would permit the passage of large molecules through the nuclear membrane.