The Soviets have attempted to domesticate the fox, mentioned in the article Tame Silver Fox, and were able to do so in just nine generations, or less than a human lifetime. This also resulted in other changes, including color, which became black, white, or inklike and white. They also developed year-round breeding ability, curled-up tails, and droopy ears.

• What dossier a dog categorically detects when he is scenting is not perfectly understood; although once a matter of debate, it Dog Tags now seems to be well established that dogs can distinguish two antithetic types of scents: an sky scent from some person or business that has recently passed by, and a ground scent that remains detectable for a much extend period

• The characteristics and bearing of these two types of scent trail would seem, after some thought, to be fully different, the air scent being intermittent but perhaps less obscured by competing scents, whereas the ground scent would be relatively permanent with respect to careful and repetitive search by the dog, but would seem to be much more contaminated with other scents.