Cycle of Fire

by Hal Clement

  The plants had changed also, though not by the same process. The leaves of the larger ones dropped away and the trunks shriveled slightly. At first the watchers had supposed that the growths were simply being killed by the heat, but this hypothesis was eliminated by the appearance of hundreds of tiny knoblike excrescences on the withered trunks. These swelled slowly, apparently at the expense of the parent plant, and finally fell free in a rain of spheres which lasted several minutes.

  Smaller, grasslike plants had simply withered, but other things were rapidly sprouting in their places. Less than an hour was required to transform the cage from a respectable representation of the landscape outside the flier to something utterly alien to all of the watchers — Dar Lang Ahn included.

  “So that’s the story!” one of the biologists breathed at last. Neither he nor any of his colleagues had been affected by the sight as Kruger had been. Of course, none of them had the same personal feeling about Dar. “I suppose we should have expected quite a lot of offspring from each individual, if this is their only means of reproduction. The population of this planet must be something terrific right: after the season change.”

  One of the other biologists shook his head negatively.

  “That part is all right,” he said, “but something else isn’t. Right now we’re just before one of the changes, and there are still plenty of animals around — carnivores as well as plant eaters — and the vegetation doesn’t look particularly moth-eaten. I’m afraid I can’t quite believe that there’s no other method of reproduction here.”

  “Wouldn’t the need for that depend on the length of time between seasons? If this ratio is the usual one it simply means that about one individual out of fifty lives through the season.”

  “Right, and the season now ending lasts about forty Earth years. I refuse to believe that such a large proportion of survivors could be expected in any wild animal over such a period. We know that they eat about as much, compared to their weights, as similar animals on Earth. How about it, Dar? Don’t new animals get started at various times during your life span?”

  “Certainly,” replied the native. “Any part of an animal will grow a whole new one, provided it is big enough. The animals we use for food certainly do that, anyway; we always leave some of the creature, for that purpose. Isn’t it that way with your animals?”

  “Hmph. There are some creatures on Earth capable of that sort of thing, but they’re fairly primitive forms. I don’t see how anything on this planet could get killed.”

  “Well, some animals don’t leave enough of their prey to grow again, of course. Then there are always things like starvation or drowning, though starvation takes a long time to shrink anything down to the point where it can’t live.”

  One of the scientists looked thoughtfully at his own right hand, on which two fingers were represented by stumps — the relic of a childhood accident. “I suppose, Dar, that it would be foolish to ask whether your own race shares this ability of regeneration.”

  “I do not see why it is foolish. Yes, we have it; though in a civilized community there is, of course, very seldom any need for it. Occasionally a victim of a glider crash or something of that sort will have to replace an arm or leg.”

  “Or head?”

  “That is a special case. If the injury is one that interrupts the regular life processes the tissues go back to the ‘beginning’ and reorganize to a completely new individual — or to several. As far as the original individual is concerned death has occurred. As I said, this sort of thing happens rarely.”

  It rather surprised the biologists, that an explanation to the phenomenon was found. However, several weeks’ work with all the facilities the Alphard had to offer did give a reasonable answer. Richter, head of the biological crew, was glad of the chance to explain it to Commander Burke. That officer had come to question him specifically on such matters; he was worried.

  “I’m bothered a trifle about these people, Richter,” Burke opened the conversation. “As you know, every ship commander that goes out from Earth gets a long briefing about the risk of introducing new species in any environment. They tell us about rabbits in Australia and Japanese beetles in North America, until we get sick of the whole business of ecology. It seems to me that we’ve run into something that might possibly be a serious competitor for humanity, if what I’ve been told about Dar Lang Ahn’s people is correct.”

  “I suppose you’ve read our summary about regeneration. I admit that these people are rather remarkable in some respects, but I shouldn’t say they constituted any sort of danger.”

  “Why not? Don’t they fit right into the picture — a creature entering a new environment, where its natural enemies are absent, and multiplying unchecked? These beings would swamp men out in a few years.”

  “I can’t see it. Dar’s people have the same natural enemies as men — any sort of meat-eating animal, as well as their usual diseases. They do have sickness, according to Dar. Anything like that would come with them.”

  “But the primary killing agent that affects the race is heat. What’s going to happen if they get established on Earth, or Thanno, or Hekla, or any of a score of other worlds you and I could name? They’d be virtually immortal.”

  “Granting that they need heat to die ‘normally,’ I think you’re forgetting something. They also need it to reproduce.”

  “Either that, or dismemberment. What happened in the Chesapeake in the days when the oystermen thought they could get rid of starfish by chopping them up and throwing them back in the water?”

  “You miss the point, Commander — and I’m afraid young Kruger has missed it, too. The really important fact is that Dar Lang Ahn’s people have to die in order to reproduce. Have you thought of it that way?” There was a long silence before the commander answered.

  “No, I can’t say that I have. That does put another color to the whole situation.” He paused again in thought. “Have you any idea of why this occurs — or rather, since it’s an obvious evolutionary development for a planet like this, how it occurs?”

  “We have. It was hard to figure, mostly because there is a good deal of evidence that this drastic climate change only started to occur in the last ten million years or so, but a certain organism of our own planet gave us the lead.”

  “What? What creature of Earth is exposed to anything like the conditions met with here?”

  “None, so far as I know; that wasn’t the sort of lead. One of the men — Ellerbee, as I recall — was working with a group of ‘hot’ animals that we’d obtained in the usual way, in one of our biggest conditioned cages. He was trying to determine whether the carnivores usually left enough of their victims to reproduce, and incidentally to see the regeneration process which Dar had told us about — we didn’t really know whether it applied to the ‘hot’ forms or not. Naturally Ellerbee was doing his best to keep track of the types and numbers of animals present, and he was a bit surprised, after a while, to find some creatures he hadn’t seen before. Fortunately he didn’t simply write the matter off as a slip in his earlier observations; he checked it carefully, and found that when the atmosphere and temperature change occurred it was possible to get animals from soil samples in which no ‘parents’ had been present.”

  “Which means?”

  “That some of the ‘hot’ forms reproduce by some form of microscopic spore which survives in the soil during the unfavorable season. Whether any of the ‘cold’ ones can do the same is still uncertain; we haven’t found any.”

  “And what does this imply?”

  “It got Ellerbee suspicious of the general theory that Dar Lang Ahn and those fire-blooded starfish are actually alternate generations of the same species. We talked over the matter at one of our regular discussion sessions and found that there was already some more evidence in. Dan Leclos had found in one type of animal a number of small, bony spheroids which experiment had showed to be the source of the ‘hot’ generation for that particular species. If they
were removed before exposing the creature to heat and nitrogen dioxide no descendants appeared, although the flesh behaved in the usual manner, while if the spheres themselves were exposed to the changed conditions they produced embryonic specimens of ‘hot’ life.”

  “I don’t see what all that means.”

  “It seems to mean that the ‘hot’ and ‘cold’ forms are completely alien types of life, which originally evolved independently. Each produced spores, or some equivalent, that were capable of surviving the unsuitable conditions.

  “In the natural course of evolution some of them developed the trick of attaching or implanting their spores in the bodies of active animals of the other type — perhaps by arranging for them to be eaten, as some parasites on Earth still do.”

  “But in that case you should be able to find the seeds, or whatever they are, in any of the creatures you examine. You said they were present in only one. How about that?”

  “That’s where the lead from Earth came in. You may know that there are some types of virus whose natural prey are bacteria. The virus makes contact with the germ, penetrates its cell wall, and after a while a hundred or so new viruses emerge from the deflated remains of the bacterium.”

  “I didn’t know that, but there seems nothing strange about it.”

  “There isn’t, so far. However, it sometimes happens that after the virus enters the body of its victim the latter goes on living as though nothing had happened.”

  “Still reasonable. There’s always a scattering of immunes in any population.”

  “Let me finish. The bacterium lives out its time and divides in the usual fashion; its descendants do the same for ten or twenty or perhaps a hundred generations. Then, under the stimulus of radiation or chemicals or for no apparent reason at all most or all of the descendants of the original bacterium collapse — and clouds of virus particles emerge from the remains!”

  “Eh?”

  “Precisely. The original virus infected its first victim, all right, in such a way that the reproductive material of the virus was divided when that of the bacterium did the same and carried on to all the descendants of that first one. Eventually some change in conditions made them revert to their usual method of reproduction.”

  “I see,” Burke said slowly. “You think that a similar ability has developed here — that every cell of a being like Dar Lang Ahn has in its nucleus the factors which will produce one of those starfish under the proper conditions.”

  “Exactly, and yet the relationship is no more a parent-and-child one than that between Jack Cardigan and his pet canary. There’s a suspicion that the chloroplasts in earthly plants bear the same relation to them.”

  “I don’t see what difference it makes, really.”

  “In a way, it might justify the attitude of the ‘hot’ creatures toward Dar’s people.”

  “Perhaps. However, nothing you’ve said eases my first worry, except your point that both forms have to die to reproduce. You’ve added one thing that bothers me more.”

  “What’s that?”

  “This business about the time in which adaptation to this climate has taken place. If you’re right, one at least of these races has evolved from a standing start to intelligence comparable with our own in something under ten million years. It took Earth a hundred times as long to do the job — maybe twice that. These things must be among the most adaptable life forms in the universe — and that’s the point where man has held the edge, so far.”

  “You’re afraid, I take it, that if they get access to human technology they’ll spread out into the galaxy and start supplanting man?”

  “Frankly, yes.”

  “Just where would you expect them to settle?”

  “For Heaven’s sake, man — anywhere! Earth — Mars — Mercury — any of fifty worlds where we can live, and as many more where we can’t! If they can’t stand them now they soon will — it’s that adaptability that has me worried. If we get into an argument with them how do we fight — how do you kill a creature that grows new arms and legs to replace the old, that produces a whole crop of descendants if you blow it to pieces with a bomb?”

  “I don’t know and I don’t think it matters.”

  “Why not?” Burke’s voice sounded almost strangled by his emotion.

  “Because, while Dar Lang Ahn could live on Earth and a lot of other worlds, and his fire-blooded opposite numbers could do the same in a higher temperature range, as you justly point out, none of the planets you mentioned provides both temperature ranges. If a group of Dar’s people decides to migrate to Earth how will the ‘hot’ folks whose relatives are riding along with them like it? Dar undoubtedly wants descendants as much as one of us; how will he feel at the thought of the starfish which develop from his body moving to Vega Two, or Mercury? What happens to his kids, then? No, Commander, I realize that most of us have decided, pretty much without discussion, that the Teacher down there by the hot springs is an opinionated, narrow-minded, dictatorial old fuddy-duddy whose opinion isn’t worth the energy used to express it, but if you’ll think a bit longer you’ll realize that he’s more far-sighted than a lot of others I could name!”

  Burke shook his head slowly, keeping his gaze fixed on the biologist.

  “I had thought of that point long ago, Dr. Richter, and I suppose you’re right in thinking that that Teacher has done the same. I’m a little disappointed, however, that you have gone no farther.”

  “How’s that?”

  “Your point is well taken — only if these races lack technical knowledge! Dar won’t mind having the gene structures which are to produce his offspring spend a few years anywhere the starfish carrying them wants to — if he knows that eventually that creature will either travel to a planet where they can develop or park himself in a mechanical refrigerator to achieve the same end. Remember, those creatures will have the same desires as regards offspring, and they will have to cooperate with Dar’s race to satisfy them. If the natives of this planet get off it, on the basis of knowledge they’ve either picked up from us or acquired themselves, there’s going to be one of the most cooperative teams in history spreading through the star clouds — and man is going to take a back seat, if he survives at all.”

  “It seems to me that that very cooperation would be a good example to the rest of us, if it happens. These races certainly aren’t very close to such a relationship right now.”

  “No, and it’s to our interest to see that they never get there. I don’t like to do it any better than you do, or than young Kruger will, but I’m afraid the only thing we can reasonably do is prevent Dar Lang Ahn from taking the knowledge he has acquired back to his people. Unless we do that we’ve given them the galaxy.”

  “You’re right — I don’t like it. How can we justify such a thing, after we ourselves have encouraged him to learn all he could?”

  “We can’t justify it,” Burke said grimly, “but we’re going to do it. Sure, I’ll hate myself for the rest of my life, but in my considered judgment it is best for the human race that Dar Lang Ahn should not see his own people again.”

  “I’m afraid you’re right, though it doesn’t make me any happier.”

  “Nor me. Well, in common fairness we’d better tell him now. I’ll call a meeting of the entire group and let anyone with any other helpful data present it. That’s about as fair as I can be.”

  “Young Kruger may not have data, but he’ll have objections.”

  “I realize that. He doesn’t know what a favor I’ll be doing him.” The biologist looked sharply at the old officer, but Burke had nothing more to say.

  XV. ASTRONOMY; LOGIC

  DAR LANG AHN heard the biological report with only his usual interest, since such phrases as fluorinated hydrocarbons and silicones still meant very little to him. He did react, however, to Commander Burke’s announcement, and the reaction was not a mild one.

  Devastating though his emotion was it did not become vocal, for Nils Kruger started talking first.
Dar listened to precisely the points about fair play, honesty, and decency that had been discussed by Burke and Richter, but did not fully understand the terms used. In any case he did not pay full attention; he was trying to decide on his own line of action.

  Argument would presumably be useless. The men would have formed their opinions on what they had learned of him and his people. He could not quite see why Abyormen constituted a danger to the galaxy, but had come to hold the opinions of the human scientists in high respect. In spite of this he found that his natural sense of duty was urging him to go against Burke’s decision — to argue, lie, or commit violence to get what he considered vital information back to his own people. A third impulse was furnished by his natural curiosity; had it not been for duty, he would have liked nothing better than traveling to Earth with his friends — if he could still call them that — and seeing some of the worlds Kruger and the astronomers had described to him. He might have started to speak, bringing his dilemma out in the open, but Kruger never gave him a chance. The boy was forgetting all the discipline that cadet training had drilled into him and coming perilously close to using personal abuse on the commander. The full significance of this escaped Dar, of course, since he had only the vaguest knowledge of Kruger’s background, but he did understand clearly that the boy wanted to let him go back to his people.

  It seemed unlikely that Kruger would win his argument with the commander; Dar did have some idea of the relative ranks involved. Could he slip out while the argument was going on and steal one of the landing boats? He had watched carefully more than once while they were being flown; could he handle one himself? With his memory there was no question of his pushing the wrong button after he had once seen the right one pushed. However, his lifetime of fiying preserved him from what would almost certainly have been a fatal error. He realized that there was much more to handling any sort of space ship than he could possibly have learned by observation alone in a couple of dozen rides.