Shufflebrain

Another item I badly needed was a dissecting microscope. There wasn't one lying around in Optometry, and I couldn't afford to buy one out of my wife's tight budget. I learned of a new ecology program starting up over in Biological Sciences, however, and dissecting microscopes were part of the equipment for the forthcoming teaching lab. And (I licked my chops!) the course wasn't scheduled to begin until the first of the year. Could I arrange a loan? The answer was yes.

Making do also meant giving up the live tubifex worm as staple for my colony. Detergents and chemical pollutants have driven these once-ubiquitous worms from all but a few waters. Since the early 1960s, I had not been able to collect them in the field, myself but had had to fly them in from New York or Philadelphia, which was totally out of the question on a make-do budget. Thus I began feeding young larvae on freshly hatched brine-shrimp embryos, which could be purchased dry by the millions for a quarter in any pet shop. When the axolotl larvae grew to about 40 millimeters in length, I weaned them onto beef liver (swiped from my wife's shopping basket).

Feeding animals on beef liver does take time. The animals must first be taught to strike. Even after they acquire the necessary experience, though, you still can't fling a hunk of meat into the dish and forget it, as you can a ball of live tubifex worms. The liver rots at the bottom of the dish, while even the experienced feeder starves.

Now there was a federal program called Work-Study, whereby the government paid all by 20 percent of the wages for students who had university-related jobs. Just as I was weaning a group of about fifty axolotls onto liver, an optometry student, Calvin Yates, came around looking for a Work-Study job. One duty I assigned him was feeding liver to the axolotls.

Calvin--Dr. Yates--later practiced optometry in Gary, Indiana. If his treatment of people matched the care he gave my salamanders, I am sure he was an overwhelming success. Calvin had what Humphrey once called a "slimy thumb"--the salamander buff's equivalent of the horticulturist's green thumb. In Calvin's presence, living things thrived. A few days after he took over the weaning job, the axolotls were snapping like seasoned veterans. Calvin also introduced a clever trick into his feeding technique. He would tap the rim of an axolotl's plastic dish and then pause a few seconds before presenting the liver. In a few days, tapping alone would cause the larva to look up, in anticipation of the imminent reward.

I paid only the most casual, half-amused attention to Calvin's routine during that time. For I had learned that my favorite species of salamander, Amblystoma opacum, lived in the area. Opacum (the marble salamander) was one of the three principal species I had been using in my shufflebrain experiments. Luckily, the opacum female lays her eggs during the autumn. Finding them can be tricky, though. Now gregarious my wife happened to meet an old country gentleman, a retired farmer who reminded her of her grandfather. In the course of casual conversation salamanders somehow came up. The man just happened to know where he could lay his hands on about 50 opacum eggs, which he let me have for a couple dollars. And by the time Calvin was weaning the axolotls, the opacum larvae had grown to just the perfect size for me to put the finishing touches on my shufflebrain project.

Opacum belongs to the same genus as does the axolotl (Amblystoma mexicanum). As a larva opacum is a shrewd, little animal, the smallest member of the genus but easily the most elaborate and efficient hunter. And what a fascination to watch! But its small size made liver-feeding quite impractical, which was also very lucky for me.

One afternoon at the tail end of an operating session, I realized that I had anesthetized one too many opacum larvae. It is against my standard procedures to return animals to stock. Yet I don't like to waste a creature, make-do budget or no. On impulse, I decided to see how well an axolotl's forebrain would work when attached to an opacum's midbrain. And I took an animal from Calvin's colony to serve as the donor.

***

The fateful moment came ten days later. I had taken my time getting to the lab that morning, walking slowly through the crisp autumn air, admiring the trees, saying "good mornings" to students along the way, and had perfunctorily seated myself at the operating table, thinking much more about the world in general than about science. I usually keep recuperating animals near the microscope and check their reflexes daily until they come out of postoperative stupor. That morning, I came in merely to take a routine daily record.