EN
Given A∈ Ωₙ, the n²-dimensional spectral unit ball, we show that if B is an n×n complex matrix, then B is a "generalized" tangent vector at A to an entire curve in Ωₙ if and only if B is in the tangent cone $C_A$ to the isospectral variety at A. In the case of Ω₃, the zero set of the Kobayashi-Royden pseudometric is completely described.