Resistivities of liquid Li-Ge alloys have been measured in the composition range from 17 to 70 at% Ge. Plotted as a function of composition the resistivity exhibits a sharp peak at 80 at% Li. This is considered as an indication for the formation of a liquid octet compound. Around that composition the values of the resistivity indicate a diffusive motion of electrons and the temperature derivative of the resistivity has a sharp negative minimum. This behaviour is compared with that of liquid Li-Si, Li-Sn and Li-Pb. The results are also related to earlier NMR data.