Early transmission electron micrographs showing pore details in negatively stained preparations of nuclear envelopes. Upper panel shows the pronounced 8-fold symmetry in the closely spaced pores of the oocyte of the newt Taricha granulosa. Lower panel depicts the oocyte envelope of the newt Notophthalmus viridescens revealing 8-fold symmetry upon rotational averaging (inset). (Upper micrograph from A. Faberge (1973) Z. zellforsch. 136: 183-190, reprinted with permission as Fig. 151; lower micrograph from Gall (1967) J. Cell Biol 32: 391, reprinted with permission as Fig. 152 from Chapter 4 (Nucleus) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. A PDF copy of the accompanying chapter is available on the ASCB's BioEDUCATE website.