The evolutionary status of the black hole candidate V 404 Cygni.

I show that the black hole candidate system V404 Cygni conforms to a simple picture of 'stripped-giant' evolution, in which an evolved secondary star of core mass Mc of about 0.20-0.22 solar mass overflows its Roche lobe. The predicted absolute magnitudes for this star give system distances of 3.5-5.1 kpc and peak X-ray luminosities of about 1.8-3.75 x 10 exp 39 erg/s. The mass-transfer rates predicted by the evolutionary picture agree well with X-ray observations.