One fine day in early June of 1832, Joly came into the Cafe Musain in a state of great excitement. He held his hands cupped together, close to his chest, and every now and then would lift them to his eyes and peer into the darkness within.

After observing this odd behavior for several minutes, Combeferre asked him, "What have you got there?"

Joly grinned and beckoned him over before moving his thumb slightly. A lopsided mouse sat on his palm. "Why on earth do you have a mouse?"

"This mouse is the offspring of twenty generations of mice who have all had their left hind legs severed. It has an extremely long left hind leg, and a normal sized right leg."

"You know what this means, don't you?" Combeferre asked, breathlessly.

"Yes!" Joly answered, holding the mouse over his head like the torch of liberty. "Lamarck is dead!"

Enjolras sprang to his feet and ran into the street shouting.

"Oh dear," Combeferre said in a very small voice.