hypothesis. He asks how a membrane, the apparent thickness of which must depend on the obliqueness of the sections, could always appear to be of the same thickness. He also asks why the endoplasmic reticulum and the Goigi apparatus, if they really do have 3-dimenional structures, usually appear as equally spaced parallel lines. If nuclear pores do in fact exist, they would only be visible if their diameter was greater than the section thickness, even then would not be of constant size.
Consequently he concludes that nuclear pores, the endoplasmic reticulum, the Golgi apparatus and the unit membrane arise as artifacts during preparation for electron microscopy. To support his argument, he points out that the original structure described by Golgi consisted of a uniform net throughout the cytoplasm, whilst under the light microscope it is 10/a diameter and under the electron microscope 1.S/al
The material was well presented and certainly stimulates thought. Even so, it is surprising that so new a film leans so heavily on the unit membrane hypothesis, particularly when the now generally accepted fluid mosaic hypothesis of membrane structure is indeed compatible with continuous movement within the cell and to a considerable extent, compatible with electron microscopic observations too.
If this film should be used in undergraduate teaching, it should only be shown as a basis for discussion to an advanced class who are already conversant with cell structure and electron microscopy. It would be ideal for inclusion in an honours student study weekend programme!