In a recent decade, experimental and theoretical studies on the structures of liquid crystals have been rapidly developed. Here the structures and diffraction patterns of several phases in liquid crystals are reviewed. They are not so simple as we thought and the molecular interactions are fairly complicated. The phase transitions in liquid crystals are discussed in comparing with the superfluid phase transition which is only one case of the phase transition observed in liquids. Ferroelectric, lyotropic, and discotic liquid crystals are briefly reviewed. The dynamical properties of liquid crystals are also discussed.

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Detailed procedures and results are represented for the steps in the crystal structure analysis of a small spherical virus. The descriptions are given for data collection, processing using oscillation photography and phase refinement by molecular replacement method. The averaged map based on the molecular replacement elucidated structural features of Southern Bean Mosaic Virus.

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Recently, triple chain silicates which belong to biopyriboles were found by Veblen and Burnham. Biopyriboles are understood as polymerization series based on the concept of pyroxene slab unit. Present knowledge of stability of triple chain silicate is briefly reviewed. The genesis of triple chain silicate in metasomatism was examined in detail on many specimens from Akatani mine in Niigata Prefecture by high resolution electron microscopy. The concept of topotaxy index was introduced here and was used to interpret the tranformation mechanism. Taking account of the mode of occurrences of triple chain silicate in metasomatism, kinetics was considered. Triple chain silicate was assumed to be formed metastably, topotactically from clinopyroxene. The author's hypothetical composition-free energy diagram and reaction coordinate-free energy diagram were proposed. Intermediate depolymerizaton process in heating experiment of hydrous biopyriboles was also directly observed by high resolution electron microscopy.

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