Beryllium abundances are determined in 38 stars of spectral types F and G, including the Sun. New observations in the ultraviolet at 6.7 A mm/sup -1/ of 15 stars have been made with the coude spectrograph of the 224 cm telescope at Mauna Kea. These data supplement values found in the literature. A model atmosphere analysis with Carbon and Gingerich (1969) models and the equivalent widths of one of the Be II resonance lines, 3131.064 A, gives the Be abundance for each of the 38 stars. Effective temperatures were found from H..beta.. photometry; values of log g were estimated from the position of the star in the (c/sub 1/, b: y) diagram.The derived Be abundances show no dependence on stellar surface temperature or B: V, and the mean abundance is Be/H=1.31 x 10/sup -11/ +- 0.36 +- 10/sup -11/. The solar system abundances are similar. This value thus represents the cosmic or universal abundance, and the origin of Be can be explained by galactic cosmic-ray spallation reactions in the interstellar gas.One-third of the stars in the temperature range 6600--7400 K have only upper-limit Be abundances and are Be-deficient. These stars are also Li-deficient. A discussion of the light-element depletion inmore » terms of diffusion (including turbulent diffusion) and convective overshoot is given. Diffusion and rotational braking appear to offer the more promising explanation of the two. (AIP)« less