Over on Twitter, my pal Cliffdotmac and I pondered the question, why not use regular supermarket potatoes as seed potatoes. He said, one of the auld timers at his allotments believed the farmers/supermarkets did something to the potatoes, treated them with chemicals to prevent them growing naturally, (which led to the Trainspotting gag from Cliff: "Choose life. Choose a career. Choose a big fucking allotment.") So, anyway, I decided to see if I could free some specimens from a Tesco bag of Maris Piper from their drug hell. I put 6 of them on a cool-ish windowsill to see if they'd chit.
Lo and behold, one of them has, (though, in fairness to Cliff's auld codger, 5 of them haven't). So I plan to sow it with the other main crop, (King Edwards, probably), clearly marked, and keep its progeny for next year, and maybe get a whole row out of it, and thereby start a dynasty of allotment Maris Pipers, rescued from the shooting gallery, seen through rehab and into the chip-pan. Voila.