Lastly, electron microscopy depends heavily on the quality of observations and interpretations. 19 For example, a common error is to call every phage head with a hexagonal outline an icosahedron although, geometrically speaking, it could also be an octahedron or a dodecahedron ( Table 2 ). The past five years have generated scores of strange publications. Some investigators of soil phages saw novel viruses in every round or oval particle or isolated tail sheath, others interpreted particles with contracted and extended tails of the same Bacillus myovirus as members of different species, and still others confused negative and positive staining or myo-, sipho-and podo-viruses. This denotes a decline in the general knowledge of viruses and of bacteriophages in particular. Misdiagnosis is particularly frequent in the interpretation of natural samples (water, soil and feces) because these may contain almost anything: algal, plant and vertebrate viruses, muscle fibers, abiogenic material, and of course the omnipresent bacterial debris of any kind. Ultimately, the human factor is the root cause of most problems: failure to maintain, repair and align an electron microscope; failure to focus properly and to correct astigmatism; improper or no specimen preparation; failure to recognize artifacts and fake viruses; absence of magnification control; finally failure to consult the now very abundant literature on electron microscopy in general and that on phages in particular. This translates as "everything that can go wrong, will." Fortunately, there are reasons to be optimistic as any man-made problems can be corrected by humans.