Trajectories of central conditions for fully convective M < 0.3  M _☉ stars as they approach the main sequence ( M>0.08  M _☉) or become brown dwarfs for Y = 0.275 and Z = 0.019. Each solid line shows T _c and ρ _c for a fixed mass, M, noted at the end of the line (when the age is 3 Gyr). The dashed blue lines are isochrones for ages of 10, 30,100, 300 Myr and 1 Gyr. The purple squares and red circles show where D and ⁷Li is depleted by a factor of 100. The green triangles show the ZAMS.