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Synaptic vesiclesToo uniform in diameterTable 2. With the exception of the Golgi apparatus, these artifacts were found by electronmicroscopy. Structures seen in unfixed cells, which are not seen in stained sections of centralnervous system, are fine granular material, nucleolonema, nucleolar membranes.If the above structures are, indeed, artefacts, how may they arise?(i) The unit membrane appearance of the cell, nuclear and external mitochondrial,membranes - as opposed to the membranes themselves - is easily explained. A line is ageometrical abstraction, because it has position but no thickness. Any real membrane has twosurfaces. Stains used in electron microscopy deposit on both surfaces, so that if one cuts any realstained membrane and magnifies it sufficiently, it must appear as two lines. The uniformity ofdistance apart or of the two 'laminae‟ arises because the electron bombardment explodes thetissue under the state, leaving a groove (Hillman, 2008, p.58);(ii) many of the reagents used in staining for electron microscopy are very near theirsolubility products. So many and heterogeneous are the agents used and the constituents of thetissue, that it is extremely likely that during the lowering of pressure in the electron microscopeor during the electron bombardment, some of the chemicals in the region will precipitate, anddeposit. There would be considerable difficulty in distinguishing the latter from cell structures;(iii) most of the mass of cells is cytoplasm and nucleoplasm, containing proteins,carbohydrates, fats and salts. When they are dehydrated, those constituents which were notdissolved or suspended in water, precipitate or crystallise. The latter would be part of theapparent cytoplasm and nuclei of stained tissue;(iv) freezing techniques are sometimes used instead of chemical fixation. Earlycryobiologists examined frozen solutions of glycerine, amino-acids and salts. These appeared inbeautiful crystalline patterns which looked remarkably similar to the cytoskeleton (Luyet, 1960;Meryman, 1966; Mackenzie and Luyet, 1967; Smith, 1961). It is a useful exercise to examine theshapes and properties of these crystalline forms;(v) the apparent two-dimensional nature of the 'unit membranes', the endoplasmicreticulum, and the mitochondrial cristae, has not formally been noticed, criticised or explained:12