I have participated in vivisections, have helped kill perfectly healthy creatures in the name of science education.

I think hunting is an easier way to dispatch an animal because you do it from a distance. You sight your target (an individual you've never seen before), pull the trigger and BLAM! Bambi's dead. Unless you're a poor shot and find your terrified quarry floundering in the bush with a shattered leg, you don't have to use your knife on anything but a lifeless piece of meat.

But you don't have anything but the knife in the lab. You must kill with your hands, the doomed creature, often an animal you've been taking care of, watching you.

The particular red-eared slider I lifted from a bucket in the turtle room and took to my physiology lab table was a complete stranger, but at the time I was keeping a tiny version of him as a pet. My red-eared slider, whom I'd named Pat because I could never figure out its gender, was small and sickly, its shell soft and warped from the malnutrition it had suffered in the wild before I found it. The turtle in my hands was wonderfully healthy; he weighed at least ten pounds, his shell smooth and dense, his crimson "ear" patches bright, his eyes clear and alert.

Too bad we were going to kill him.

We were doing the Heart Lab, a lesson designed to give all of us hands-on knowledge of how a living heart works. Obviously, to look at a beating heart, you have to do surgery on a live animal. And since my small college's biology department was utterly unequipped to recuperate creatures from any sort of surgery, much less open-heart work, whatever animals we used for the lab were going to die.

Red-eared sliders were ideal candidates for the experiment because, being turtles, their bodies will continue to function for some time after their brains have been destroyed. And in this case, destroying, or "pithing," the turtle's brain was the only anaesthesia we could offer it; if we used a narcotic to put him under, his heart rate would dive into the basement and the experiment would be ruined.

The pithing procedure was difficult. Our turtle knew something was up. He pulled his head and legs into his shell and glared at us from beneath the bony overhang of his carapace.

But we had to get to his head to pith him. So one of my lab partners held him down on the board and another rapped him on the nose with a pair of heavy-duty surgical forceps in the hope that he would get angry and chomp them, thus giving us a handy way to pull his head out.

He only closed his eyes and pulled in a little tighter. So I and my remaining lab partner started prodding his recessed rear legs in the hope our poking would aggravate him.

It finally did, and he bit the steel forceps. The young man wielding the forceps yanked the turtle's head free of his shell, and another student whipped a loop of string around his neck.

The lassoed turtle struggled to get free, his claws scraping against the plywood. The student holding the forceps swore softly and told the young woman holding the steel probe to hurry up.

She slid the needle-tipped probe into the back of the turtle's head, pushed through the thin skull into the almond-sized brain, and made a quick cranking motion.

The turtle went limp. She pulled the probe out. There was very little blood, just an angry red hole in the back of the turtle's head.

I have no doubt that the turtle could no longer feel a thing. His eyes were filmy and cold, like the eyes of iced fish at a supermarket. His reptilian soul was gone; he'd turned into a piece of dying meat that happened to look like a turtle.

We flipped the turtle onto his back and tied his head and limbs to raised steel screws in the plywood. Our lab instructor came to our table with a small electric circular saw. The serrated blade screamed through the bony bridge connecting the upper and lower portions of the turtle's carapace.

The air was filled with the stench of blood, pond water and burnt bone.

We pulled and cut the belly shell away from the turtle's body, and once we'd uncovered his body cavity we could see his heart, still pulsing. We cut through more membranes to fully expose it, and then we lifted it out of its cavity, blood vessels intact, and hung it in a little wire basket that led to a cardiograph, a machine that measured the turtle's heartbeat and scritched corresponding jags and flat valleys on a roll of paper.

The experiments began. I periodically squirted the heart with blood-pH saline solution to keep it from drying out and to wash off the chemicals we used to alter its beat.

The first chemical was a nicotine solution, which made the small red knot of muscle pulse more quickly. We dutifully recorded our observations in our lab books, washed off the nicotine, then applied a barbiturate solution that made the beat slow to almost nothing. We recorded more observations, then put on more of the barbiturate, making the heart stop entirely, the cardiograph flatlining.

We used a pair of electrified metal probes to shock the heart back to life. We used more chemicals to produce more effects, but finally the lab came to an end, and we wrapped the carcass in a black trash bag and put it in a garbage bin with the five other turtles that had been sacrificed for my classmates' education.

Was our education worth killing turtles? I don't know; I guess everything hinges on what value you put on having properly trained veterinarians and biologists who know first-hand what a heart ought to do, and what value you put on the life of a turtle from a non-endangered species.