Shufflebrain

Julius had become a pain the neck for me. In those days, I feed my animals exclusively on tubifex worms which had to be flown in fresh from New York every week or so. The shipping costs made the worms several orders of magnitude more expensive per unit weight than filet mignon. In few minutes, Julius could devour two weeks' supply of worms for the entire colony. I'd tried feeding him on guppies, on which I was overrun. But the clever little fish, which cohabited one of my sinks with him, were far too quick for Julius. Carl, too, had a guppy over-supply problem. He asked if axolotls can catch guppies. "Too stupid," I said. Carl frowned and his ears blushed. Although he said nothing, I had the distinct impression that he disliked my remark about Julius's cognitive ability.

One afternoon some weeks after he saved me from recycling Julius through the snapping turtles by accepting my gift, Carl burst into my lab, took me by the sleeve, and dragged me back to his quarters. He wanted to show me something but wouldn't say just what. I knew it had to be good.

Julius was in a large enamel pan. I recoiled at the sight of him. He'd almost doubled his size since I'd last seen him. When he arched his muscular back and looked up at me, I was glad a coarse mesh screen covered his pan.

Carl netted a guppy and transferred it into a small beaker of water. He flicked off the overhead light. The room turned an eerie brownish color in indirect light from the machines and indicators. Carl turned on a spotlight and aimed it at one corner of Julius's pan. The axolotl alerted and in a few seconds glided to the spot and parked right at its edge. Carl poured the guppy through the mesh, into the spot of light. Bam! The guppy vanish virtually as it hit the water.

"That's not fair!" I protested. I thought I could make at a grin on Carl's face. He ignored my remark, but as he netted another guppy he told me that Julius had learned that trick on the first day.

Carl poured the second guppy into the pan, but this time over on the opposite end from Julius and the pernicious spot of light. The axolotl's massive bush of external gills seemed to tense ever so slightly, but he remained parked. Now light strongly attracts guppies. And what do you suppose this poor guppy in the tank with Julius did? It swam to the spot and virtually into Julius's waiting jaws.

"Maybe," I conceded.

Carl turned off the spotlight, flicked on the overheads and went for a third guppy. Carl definitely was grinning, I noticed. In went the third guppy, again at the opposite end of the pan from Julius. This time there was no spot of light to attract the victim or hold Julius's attention. But shortly after the fish went into the tank, Julius turned. He began to chase the guppy all over the pan. Just as I was about to call him stupid again, I became aware of a change in the beast's behavior. He wasn't putting his fury into the chase, as he did back in my lab, wasn't lunging and thrashing and flopping ineffectual--isn't really trying to catch the guppy, I realized. Now his purpose was almost casual: a lazy flick of the gills here, a swush! of the giant tail there--just enough to keep the guppy frantically on the move, up and down and back and forth across the pan. The chase continued for perhaps two minutes, the fish moving flat-out almost constantly. Then smoothness began to disappear from the fish's movements. It's becoming fatigued, I thought. Just then, Julius began to close in, steadily, inexorably, boxing the worn-out little fish into a corner. Suddenly the water churned as though a volcano had erupted in its depths. Julius feinted to his left with his gills. The guppy darted to the right. But Julius was already on the ill-fated path. And the fish was suddenly gone.

Carl had trained Julius to associate light with the imminent presence of food. But the beast had somehow managed to learn the rest of the hunt by himself. Conventional tests of learning would not even hint at such capabilities. Carl had allowed Julius's behavior to determine the training. Like the ethologists, Carl respected behavior in the large, which made him a master of it in the small.

***

Carl often came to my lab around ten in the morning for his coffee break. We'd sometimes spend hours or even the rest of the day chewing and speculating about anything from the chemical transfer of memory to the social behavior of apes to war, which was on everyone's mind at the time.

One morning, he arrived a little earlier than usual. Squatting, balancing a coffee cup on one knee and using the floor drain as an ashtray (even scientists smoked in those days), he asked, "How hard is it to add an extra eye to a salamander?" He went into a coughing spasm but, between paroxysms and drags on his cigarette, managed to phrase a very interesting idea.