Fig. 9. Abundances of lithium and beryllium as a function of [Fe/H] for 9 halo stars from Smith et al. (1998) and 5 disk stars from the present paper. Open circles indicate the total Li abundance and filled circles the ⁶Li abundance or an upper limit. Open squares refer to the Be abundance adopted from Gilmore et al. (1992) and Boesgaard et al. (1999b). The big symbols indicate meteoritic abundances from Anders & Grevesse (1989). The upper full drawn line is a fit to the `Spite plateau' of lithium abundances for and to the upper envelope of the Li abundance distribution for disk stars (see Fig. 7 of Lambert et al. 1991). The lower full drawn line is a linear fit to the beryllium abundances with a slope of one, and the long-dashed line shows the corresponding relation for ⁶Li if ⁶Li /Be = 5.8 as found in meteorites and as predicted from spallation of CNO nuclei by high energy cosmic rays. The dotted line represents the evolution of ⁶Li in the model of Fields & Olive (1999a,b), the dashed-dotted line the model of Vangioni-Flam et al. (1999) and the short-dashed lines refer to the model of Yoshii et al. (1997) for the halo and the disk, respectively