1. Galactic Structure in the Direction of the Polar Caps -- Introductory Remarks -- One Galactic Structure at Lower z Distances - Space Densities and Motions - The Solar Neighbourhood - M Dwarfs - Missing Mass -- M Dwarfs at Lower z Distances -- Available Stellar Data in Galactic Polar Areas -- Bibliography on Galactic Structure in the Direction of Polar Caps -- M Dwarfs and the Missing Mass -- Some Research Programmes into Galactic Structure at the Galactic Caps Under Way at the Royal Greenwich Observatory -- The Space Density of M Dwarfs - An Observational Program -- The Luminosity Function of Late-Type Main-Sequence Stars in the Direction of the North Galactic Cap -- Galactic Mass Density in the Vicinity of the Sun -- The Frequency of Faint M Giant Stars at High Galactic Latitudes -- General Discussion of Topics in Part One -- Two Galactic Structure at Higher z Distances - Space Densities and Motions - Different Stellar Populations and Chemical Abundances -- The Stellar Distribution Above the Galactic Plane: An Introduction -- Some Results of Classification of Stars in Kapteyn Areas Applied to Galactic Structure in NGP -- Mean Chemical Abundance of the F Stars as a Function of Distance from the Galactic Plane -- RGU Three-Colour-Photometry Towards the NGP: Halo-to-Disk Mass Ratio -- Density Law, Vertical Distribution and Vertical Gradient of Metal Abundances for G and K Giants -- Polarization Measurements and Extinction Near the NGP -- Parallaxes of Selected Stars Near the NGP -- Progress Report on a Search for Parallax Stars in the Region of the South Galactic Cap -- Search for Large Radial Velocities in the Direction of NGP Using the Fehrenbach Techniques -- The Gravitational Field of the Galaxy in the z Direction -- Berkeley Studies of Faint Stars at High Latitudes -- Swedish Programmes Concerning the z Distribution of Stars -- Studies of A and F Stars in the Region of the NGP -- The Distribution of Field Horizontal-Branch Stars in the Galactic Halo -- A New Program to Determine K (z) from Main Sequence Stars -- Objective-Prism Radial Velocities at High Latitudes -- Discussion of the Calculation of the Density Law (Dz) -- Motions of Near-Polar K-Giants Along the z Coordinate -- General Discussion of Topics in Part Two -- Three Summary and Conclusions - Present Results and Future Problems for Study -- The Role of Proper Motions in Determining the Luminosity and Density Functions -- Concluding Remarks Part Two -- Current Results and Suggestions for Future Work -- 5. Stellar Atmospheres as Indicator and Factor of Stellar Evolution -- Introduction-Observational Evidence -- Introductory Talk -- Observational Evidence for Atmospheric Physical Characteristics Relevant to Stellar Evolution -- Behaviour of Microturbulence with Evolution -- Observational Evidence for Atmospheric Chemical Composition Peculiarities Relevant to Stellar Evolution -- Stellar Atmospheres as Boundary Condition of Internal Structure -- Sensitivity of Internal Structure to the Surface Boundary Condition -- Boundary Conditions with Mass Loss: General Considerations -- Mass Loss in Stars of Moderate Mass by Stellar Winds and Effects on the Evolution -- Boundary Condition with Mass Loss: The Radiatively-Driven Wind Model -- Alteration of Surface Chemical Composition of Stars by Transport Phenomena -- Stratification of Elements in a Quiet Atmosphere: Diffusion Processes -- Competition Between Diffusion Processes and Hydrodynamical Instabilities in Stellar Envelopes -- Alteration of Surface Chemical Composition of Stars by Nuclear Reaction -- Mixing Between Burned Core Material and Surface Layers -- Decay of Light Elements in Stellar Envelopes -- Conclusion -- 6. The Small Scale Structure of Solar Magnetic Fields -- Observations of Small-Scale Photospheric Magnetic Fields -- Small Scale Solar Magnetic Fields: Theory -- Some Comments on the Measurement of Small Scale Strong Magnetic Fields on the Sun -- Line Profiles of Faculae and Pores -- Facular Models, the K-Line, and Magnetic Fields -- Small Magnetostatic Flux Tubes -- Flows in Magnetic Flux Tubes -- Discussion -- Concluding Remarks -- 7. The Impact of Ultraviolet Observations on Spectral Classification -- Present Status of Spectral Classification in the Conventional Wavelength Range with Emphasis Upon Early-Type Stars -- Spectral Classification of Early-Type Stars from the Low Dispersion Ultraviolet Spectra -- Spectral Classification of B and A Stars from the Line Features of S2/68 Spectra -- Behaviors of B Star Continua and Absorption Features Determined from the TDl S2/68 "Ultraviolet Bright Star Spectrophotometric Catalogue" and from Copernicus Spectra -- Discussion -- Spectral Classification Using ANS Photometric Data -- Spectral Classification with Objective-Prism Spectra from Skylab -- Discussion -- An Atlas of Ultraviolet Stellar Spectra -- A New Temperature Scale for B Stars Based on OAO-2 Data -- Extreme Ultraviolet Observations of White Dwarfs -- The Near Ultraviolet Spectrum of Fe III as a Classification Criterion -- A Catalogue of 0.2 Å Resolution Far-Ultraviolet Stellar Spectra Measured with Copernicus -- Spectral Classification from Copernicus Data -- The Ultraviolet Spectrum of ? Lyrae -- The Mg II Features Near 2800 Å and Spectral Classification -- Discussion -- Concluding Remarks -- Observational Evidence of the Heterogeneities of the Stellar Surfaces -- Heterogeneity of the Solar Atmosphere -- The Heterogeneity of Surfaces of Magnetic Ap Stars -- Starspots on by DRA-Type Stars -- Starspots on AR Lac Type Stars -- Direct Observations of the Heterogeneity of Supergiant Disks -- On the Spottedness and Magnetic Field of T TAU-Type Stars.