"Yeah ... and then that raises another question. How old are these things? And how big are they going to get? And does their appetite keep pace? And what is their full size? Or is this it?" I sat down on the edge of one of the tables, facing the glass wall of the millipede cage. I began chewing on the end of my pencil. "Too many questions-" Hanging around the millipedes was affecting my eating habits. I folded my arms across my chest. "And what if we're not asking the right questions in the first place? I mean, what if it's something so simple and obvious that we're overlooking it?"
"Hm," said Ted; then, "Maybe they're not getting the right kind of food-and that's why they stay so hungry......"
"Hey!"
Ted looked up. "What?"
I pounced on the thought. "Try this: maybe they're dextro- and we're levo--they're made out of right-handed DNA! And they need right-handed proteins to survive! And this is a left-handed world!"
"Um," said Ted. He scratched his nose and thought about it. "Yes and no. Maybe. I have trouble with the right- and left-handed idea. I don't think it's possible. It's certainly improbable."
"The worms themselves are improbable," I pointed out.
He scratched his nose again. "I think the fact that they can safely eat any Earth-based organic matter without immediately falling down, frothing at the mouth in deadly convulsions, is a pretty good sign that our respective biologies are uncomfortably close. If I didn't know better, I'd say almost related."
Another idea bobbed to the surface. "Well, then-try it this way. Earth isn't their native planet, so maybe they have to eat a lot of different things to get all of their daily requirements. I mean, their metabolisms must be different because they've evolved for a different set of conditions, so they have to be unable to make the best use of Earth-type foods-it follows, doesn't it? -so they'd have to increase their intake just to survive."
"Um, but look, if that were true of the millipedes, then it would have to be true for the worms. They'd have to be even more ravenous than they already are. They'd be eating everything in sight."
"Well, they do, don't they?"
He shrugged. "Who knows what's normal for a worm?"
"Another worm?" I suggested.
"Mm," he said. And then added, "-Except, there are no normal worms on this planet."
"Huh?" I looked at him suddenly.
"It was a joke!" he said.
"No-say it again!"
"There are no normal worms on this planet."
"What did you mean by that?"
He shrugged. "I don't know; it just seemed ... obvious. You know? I mean, we don't know what the worms are like in their own ecology; we only know them in ours-and we don't even know how they got here. So if there's something-anything-that's making them or their behavior atypical, we wouldn't know, would we? And neither would any other worm on this planet, because they'd all be experiencing the same effects."
"That's great!" I said, "It really is-I wonder if anyone else has realized that yet."
"Oh, I'm sure they have-"
"But I'll bet that's part of the answer. We're dealing with crazy Chtorrans! And I like your other idea too-about something keeping their blood sugar permanently low. I just wish I had a good biological justification for it." I scribbled it into my notebook. "But it fits in with something else. Here, look at these-" I went rummaging through the mess on the desk behind me and came up with a folder marked UGH. I pulled out a sheaf of color eight-by-tens and passed them across. He stood up to take them. He leaned against the table and began to leaf through them. "When did you take these?"
"This morning, while you were on the terminal. I finally found my close-up lenses. There's some real high-power stuff there. Look at the structure of their mouths."
He grimaced. "They look like worm mouths."
I shrugged. "Similar evolutionary lines, I guess. What else do you see?"
"The teeth are like little knives."
"You notice anything else? The teeth are slanted inward. Here, look--compare these two pictures where he's eating the cigar. When the mouth is at its widest, the teeth are pointing straight up and down and just a little bit outward; but as the mouth closes, they curve inward. Here, see how they mesh? Once a millipede bites something, the teeth not only cut it, they push it down the throat. A millipede can't stop eating-not until the object is finished-because he can't let go. Every time he opens his mouth, he automatically takes another bite; every time he closes, he pushes it down his throat. That's why his teeth have to grind and cut and slash--otherwise, he'd choke to death."
"Um, I doubt that last," he said. "I don't think they're capable of choking. With a mouth arrangement like that, they wouldn't have a swallowing mechanism that could so easily kill them. It would be self-defeating. I'd guess that the arrangement of the teeth is so they can get a good hold on their prey and, if nothing else, get one good bite out of it-like Louis."
"Have it your own way, Perfessor-but I watched him eat the cigar, and that's the way he used those teeth."
"But, Jimbo-that doesn't make sense. What happens to the little bastard who gets stuck to a tree?"
"He eats or dies," I offered. "Remember what you learned in schooclass="underline" `Mother Nature doesn't give a shit.' "
"Um," Ted said, shaking his head. He continued paging through the photographs. "How did you shoot this one?" He was staring down the wide-open mouth of one of the millipedes.
"Which one? Oh, that. I shot that through a pane of glass. There's a spot of grease smeared on it; he's trying to bite it off. The focus isn't so good because of the grease, but it was the only way I could look down his mouth. They learned real quick that they couldn't get through the glass, so they stopped lunging at it when I held up a finger. That's why the grease. Here, this one's sharper-this was before he scratched the glass."
Ted peered close. "Hand me that magnifying glass, will you? Here, look-what do you make of this?"
"Hey! I didn't notice that before-a second row of teeth!"
"Mm," said Ted. "I wonder if he ever bites his tongue."
"Those are molars!" I said. "See? They're not as sharp. The first row is for cutting; these are for grinding. And look-do you see anything farther back?"
"Uh, I'm not sure. It's awfully dark down there."
"We can digitize this and bring up the resolution, but doesn't that look like a third row?"
"I can't tell. It could be."
I looked at him. "Ted, maybe these things have teeth all the way down their throats. That's why they can eat so much, and so many different things. By the time the food reaches the stomach, it's been ground to pulp. They'll still need strong stomach acids, but now the food has a lot more surface area exposed to the action of the enzymes."
"Well, this makes them a little more . . . believable." Ted grinned. "I find it very hard to trust any kind of creature that eats tennis shoes, wallpaper and baseballs, not to mention bicycle seats, clotheslines and Sergeant Kelly's coffee."
"Ted, give me a break. Please."
"All right-they wouldn't drink the coffee. That's probably what the Chtorrans use in that corral fence to keep them from getting out-Sergeant Kelly's coffee grounds."
"Oh, no," I said. "Didn't I tell you?" He looked up. "What?"
"You should have guessed. What's the one thing the millipedes won't eat-the one organic thing?"
He opened his mouth. He closed it.
"That's right," I said. "Used food. No creature can live in its own excrement-those are the things its metabolism can't use. And that's what the worms put between the double walls of their corral. As soon as the millipedes sense it, they back away."
"Wait a minute, boy-are you telling me the worms are going around gathering up millipede droppings for fence insulation?"
"Not at all. I didn't say anything about millipede waste. I just said it was waste"-he opened his mouth to interrupt; I didn't let him-"and it's not terrestrial waste either. Remember we were wondering why we never found any worm droppings? This is why. Evidently, the worms have been using it to keep their `chickens' from escaping. The worms and the millipedes must be similar enough so that it doesn't make any difference. What a worm can't use, neither can a millipede. The tests on the droppings from the enclosure and the specimens we've got here show a lot of similarities. Mostly the differences are dietary, although a lot of the special enzymes don't match up. If I had more sophisticated equipment, I'd be able to spot the subtler differences."