Gumbril’s first instinct was to rush up the stairs and hide in the first likely-looking corner. But he pulled himself together at once. He was a Complete Man, and Complete Men do not hide; moreover, he was sufficiently disguised to be quite unrecognizable. He stood where he was, and listened to the conversation.

“The rabbit,” continued the young man, and with his bright eyes and staring, sniffing nose, he looked like a poacher’s terrier ready to go barking after the first white tail that passed his way; “the rabbit naturally develops the appropriate resistance, develops a specific anti-eye to protect itself. I then take some of its anti-eye serum and inject it into my female rabbit; I then immediately breed from her.” He paused.

“Well?” asked Shearwater, in his slow, ponderous way. He lifted his great round head inquiringly and looked at the doggy young man from under his bushy eyebrows.

The doggy young man smiled triumphantly. “The young ones,” he said, emphasizing his words by striking his right fist against the extended palm of his left hand, “the young ones are born with defective sight.”

Thoughtfully Shearwater pulled at his formidable moustache. “H’m,” he said slowly. “Very remarkable.”

“You realize the full significance of it?” asked the young man. “We seem to be effecting the germ-plasm directly. We have found a way of making acquired characteristics....”

“Pardon me,” said Gumbril. He had decided that it was time to be gone. He ran down the stairs and across the tiled hall, he pushed his way firmly but politely between the talkers.

“... heritable,” continued the young man, imperturbably eager, speaking through and over and round the obstacle.

“Damn!” said Shearwater. The Complete Man had trodden on his toe. “Sorry,” he added, absent-mindedly apologizing for the injury he had received.

Gumbril hurried off along the street. “If we really have found out a technique for influencing the germ-plasm directly ...” he heard the doggy young man saying; but he was already too far away to catch the rest of the sentence. There are many ways, he reflected, of spending an afternoon.