Tenthag sat stunned. It was as grandiose a notion as he had ever dreamed of, and he was hearing it stated in real time, in real life, as cold potential fact.
He husked at last, "I'm not sure, even yet, what it is you want of me!"
"About as much of your mantle as Pletrow could scrape off with one claw ... Ah, but a final and important question: do you recognize this lady as one of your own species?"
Gveest came to a halt directly confronting Tenthag, and waited.
"Of—of course!"
"But I'm not," said Pletrow, and descended from her branch to stand by Gveest.
"But I could pair with you!" Tenthag exclaimed, beginning to be more afraid than even at the height of the storm on his way hither.
"That's so. But we wouldn't bud."
"How can you be sure? I know mostly it doesn't happen nowadays, and I myself was the last on Neesos, but—Oh, no!"
Fragments of what he had learned by chance during his time as a novice courier came together in memory and made terrible sense. He waited, passive, for the truth to be spelled out.
Gveest announced it in a rasping voice.
"Here, and elsewhere around the planet, we have tasted the fossil record. We hunted above all for our common ancestors. We haven't found them. What we have found, and the discovery at Neesos was its final proof, is two separate species which evolved in total symbiosis. You and I, Tenthag, can't reproduce without the mediation of that species which evolved with us and gradually took over the role of bearing our young. We must have been in the closest competition, craws of years ago, equally matched rivals for supremacy. One species, though, opted for acceptance of the other's buds, while mimicking to perfection its behavior—as far as speech, as writing, as intelligence! And we aren't alone in this! Why, for example, does one only tame female barqs—briqs—junqs—porps? Those are the malleable, the pliant ones, who adopted the same course as what we call our females, at about the same time in the far past as we were establishing our rule over dry land! We are the highest orders of what some folk are pleased to call 'creation'—though if indeed some divine force called us into existence, I personally would have been glad to give that personage a bit of good advice!"
He was pulsing so hard, Pletrow turned to him in alarm and laid a friendly claw on his back. In a moment he recovered, and spoke normally.
"Well, anyway!" he resumed. "We hypothesize that in the early stages it was approximately an even chance whether implantation of a bud resulted in offspring for the 'male' version, the implanter, or the recipient, whose hormones were provoked into reproductive mode by impregnation and sometimes outdid the invader, thereby budding a female. We know parasitic organisms, especially among jenneqs, which still depend on the host's hormones to activate their buds; sometimes they lie dormant for a score or more of years!
"But at just about the tune the New Star is said to have exploded, wherever and whatever it may have been—I'm no astronomer, but they say it was somewhere around the Major Cluster—something provoked the 'female' species into yet another round of mimicry. It must have been a valid defense technique at some point in the far past, but extending it has cost them and us our reproductive capability. Tenthag, when Pletrow confronted you, were you not shocked at how male her exudates appeared?"
"I was," said Pletrow before Tenthag could answer. "It's the survival of us all that is at stake. New friend!"—she spoke as she advanced on Tenthag, mantle open in the most intimate of all postures—"do help Gveest! Don't turn him down! I cringe before you and invoke your aid!"
Suiting her actions to her speech, she shrank to two-fifths of her normal height, and bent to touch the courier's pads.
"It is other than my familiar duty," Tenthag achieved at last. "But I was instructed to put myself at Gveest's disposal absolutely, so—"
Pletrow uttered a cry of joy, and as she rose scratched the underside of Tenthag's mantle, which by reflex he had opened as to greet her. Before he could even react to the trivial pain, the threatened storm broke over Ognorit, and the house's retracted leaves unfolded, shutting out the sky, so as to channel the precious water to the ditch around its roots.
Instantly there was a clamor from the animals outside, for they knew this gift from heaven would result in an explosion of funqi and other food.
"Long ago," said Gveest, during the brief dark before the house's luminants responded, "there must have been a clash between symbiosis and extinction. Our ancestors preferred symbiosis, so we have to accept it. But the natural system was so delicate, so fragile, that even the explosion of a distant star could ruin it. It's up to us to create a better, tougher one. And this gift from you, Tenthag"—he held aloft the scrap of mantle-skin which Pletrow had passed to him—"may provide us with the information that we need. If it does," he concluded dryly, "they'll remember you one day as a savior like Jing!"
"And if it does," Pletrow promised as the luminants grew brighter, "I'll make amends to you for that small theft of your own substance. I want—oh, how I want!—to bear a bud!"
She clutched him to her for a moment, and then the company dispersed, leaving Tenthag alone with his mind in tumult.
V
In its way, Ognorit proved to be a greater wonderland for Tenthag even than Bowock on the day of his arrival there. Never had he seen a place where everything was so single-mindedly dedicated to one common goal. The island was a maze of experimental farms, pens for livestock, streams and rivers dammed to isolate breeding populations of fresh-water fish, salt-water pools above tide-level kept full by musculator pumps ... and everywhere there were exposed fossils, revealed when thin sheets of compacted clay or slate had been painstakingly separated. He was able to taste for himself how ancestral forms differed from modern ones, though the faint organic traces were evaporating on exposure to the air.
"If only we left behind something more durable than claws and mandibles!" said Pletrow wryly; to compensate for her irascibility she had undertaken to act as his guide, and was proving an agreeable companion. Gveest, once possessed of the tissue-sample he had asked for, had vanished into his laboratory, barely emerging for a bite of food at darkfall. "Suppose," she went on, "we'd had solid shells like mollusqs, or at least supporting frames like gigants! But I suppose the lesson to be learned is that the plastic life-forms do better in a changing environment. Once you develop rigidity you're at risk of extinction."
But aren't we? Tenthag suppressed the thought, and merely requested evidence for Gveest's amazing claim about the male and female of the folk actually being separate species.
Much of what Pletrow offered in answer, Tenthag had already partly grasped. Until he went to Bowock, he had been unacquainted with ideas like "symbiosis" and "commensalism"; however, as soon as they were spelled out in terms of, for example, the secondary growths on a junq's back, he instantly recognized how well they matched ordinary observation. And the notion of plasticity was not at all foreign to him. Since childhood he had known about creatures which seemed not to mind what part of them performed what service. If one took care not to dislodge it from the rock where it had settled, one could literally turn a sponqe inside-out, and the inner surface that had been its gut would become a mantle, and vice versa. But he was astonished by a demonstration Pletrow performed for him with a brollican, a mindless drifting creature from the local ocean, avoided by the folk because of the poison stings that trapped the fish it preyed on. To indicate how far back in the evolutionary chain symbiosis must reach, she carefully peeled one of the things apart, dividing it into half a score of entities so unalike one could not have guessed at a connection between them. Then she tossed food into the pool, and within a day each portion had regenerated what it had been deprived of.
"But if you split them up so completely, how is that possible?" demanded Tenthag.
"Because you can't split them up completely. Enough cells from each of the components enter the common circulation to preserve a trace of the whole in every segment, but they remain dormant so
long as suppressor chemicals are circulating too. When they stop, the cells multiply until they once again reach equilibrium. I'll show you under the microscope."
Sometimes dazed, sometimes dazzled, Tenthag thereupon suffered through a crash course in modern biology. On the way he learned about the invention of musculators and nervograps—a web of the latter, connected to various sensitive plants, reported results from outlying pens and plots and pools—and about the buoyancy of cloudcrawlers, whose gas-distended bladders had furnished the earliest proof that air was not one substance, but a mixture, and about a score of other matters he had previously felt no interest in.
Clacking his mandibles dolefully, he said at last, "And this incredibly complex, interlocking system could be put in danger by something happening out there in the sky?"
"Ridiculous, isn't it?" agreed Pletrow. "Almost enough to drive one back to astrology! But every line we pursue leads us to the same conclusion. Now we think it may have to do with the fact that some kinds of light can burn. You've used burning-glasses?"
"Well, naturally! I grew up with them."
"But do you realize there are kinds of light too wide to see, and also too narrow?"
After proving her point with a small fire and a black filter that allowed no visible light to pass, yet transmitted heat without any direct contact, she introduced him to mutated creatures from the rest of the Lugomannic Archipelago. This was her specialty, and she waxed eloquent over the creatures she kept in pens on the north shore: vulps, snaqs and jenneqs all somehow wrong—lopsided, or looking as though one end of an individual did not belong with the other, or missing some external organ, or boasting an excess of them. Tenthag found the sight repulsive, and with difficulty steered her away from the subject, back towards the crisis facing the folk.
If anything, what she told him next was even more disturbing, for she illustrated it with cells cultured from his own mantle, and invited him to compare them with those recovered from Prefs—and then calmly took a sample of her own tegument to complete the argument. All his life, like virtually everyone in the world, Tenthag had been conditioned against bringing anything sharp towards his own, or anyone's, body. A claw-scratch, such as she had inflicted on him, was nothing, but the risk of having a major tubule punctured, with consequent loss of pressure, was terrifying; it could lead to being permanently crippled. Among glass-workers this was a particularly constant danger. Yet here she was applying a ferociously keen blade to her own side—to judge by the scars already surrounding the area, not for the first time!
Sensing his disquiet, she gave a harsh chuckle.
"They say Jing's Rainbow was deformed, don't they? It can't be too disastrous to lose a little pressure ... but in any case I've had a lot of practice. There we are! Now you can compare one of my cells with one from the female they found at Prefs. You'll notice it's far more like the male's, or, come to that, your own, than it is like hers."
Struggling to interpret the unfamiliar details exposed to him, Tenthag sighed.
"I'm going to have to take your word for it, I'm afraid. I simply don't know what to look for. Can't you tell me, though, what became of our original—uh—females?"
"There never were any," was the prompt response.
"What?"
"Females—that's to say, versions of what we're used to thinking of as females—seem to have occurred very early in the evolutionary process. But prior to their appearance, as is shown by primitive creatures like the brollican, the standard pattern was well established: clusters of simple organisms banded together for mutual advantage and shared a circulation, a chemical bath, which controlled the reproduction of them all. That, though, works only up to a certain level of complexity. If I chopped a claw off you, you couldn't regrow it, could you? And reproduction is only an elaborate version of regrowth. But—and here's the main problem—within any single organism there's always decay going on. To renew the stock, without aging, and to evolve, calls for some sort of stimulus, some infusion of variety; what, we don't yet know, but we're sure about the principle. We assume it comes from the use of the symbiotic species, whose chemical makeup is much more unlike the donor's than outward appearance would suggest. Or at least it used to be. Now we're back to the change dating from the New Star, and the latest outburst of mimicry, which seems now to be going clear to the cellular level. At all events"—Pletrow briskened, evading the subject that was closest to her pith—"there never were specific females for the folk. Our species evolved together from that stage, craws of years ago, when it became impossible for either of us to continue providing the necessary variant stimuli from our own internal resources. So to say, we'd become so completely efficient as a single organism that we could no longer be peeled apart, and identity had supplanted variety. Probably you males"—with a wry twitch of her mantle—"were essentially parasitic, but you must have been amazingly successful, or you'd never have attracted such a promising species as us females into dependence!"
Controlling himself with extreme effort, Tenthag said, "If Gveest's research is successful, and his techniques can be applied to—to us, what will it involve?"
"Modification of another permanent symbiote that will survive transmission into our own bodies by way of the food we eat, and then restore the original bud-reaction."
For a moment the scope of the plan took the air from Tenthag's mantle. Eventually he husked, "But what about numbers? Gveest himself has said it will be necessary to build up the food-supply—that he had to do it here before trying his methods on vulps and snaqs and so on. Suppose we do suddenly find we can produce buds, if not every time, then twice as often as before, five times, half-a-score times: might we not outstrip our resources?"
"Gveest plans to give us new delicious foods. You've tasted some. But in any case..."
She fixed him with so piercing a glare it transfixed him to the inmost tubule, and her voice was like a prong as she concluded:
"Let the future take care of itself! I only know one thing! I mean to bear a bud before I die!"
VI
After so long a delay that Tenthag was afraid he might lose control over Flapper, who should either have departed on a new voyage or been retamed in fresh water, Gveest emerged weary but triumphant from his laboratory to announce he had no further need of Tenthag's presence.
"We've successfully established a reproducible strain of your cells," he explained. "That will furnish us with all the data we require. You've performed an invaluable service, Master Courier! Permit us, in return, to re-equip your porp."
"Thank you, but I'm content with the growths that she already bears," was Tenthag's stiff reply. "Besides..."
He hesitated, not wanting to be tactless to this elderly scholar who was, after all, an uncontested genius and on the verge of a breakthrough which might benefit the whole planet.
Might...
It was pointless, though, trying to elude Gveest's weather-sense. Dryly he said, "You're concerned about the probable success of my work. Pietrow told me. That's why I'm disappointed that you won't let me refit your porp. Now we shall have to signal the People of the Sea and let them spread the first stage of our techniques."
"I—I seem to have misunderstood something," said Tenthag slowly.
"So you do, and I'm surprised." Gveest turned to pad up and down along the stretch of beach where they had met, glancing now and then towards Flapper, fretful at her long confinement in the shallows. "I know as well as anybody that, unless we vastly increase our food resources first, doubling or trebling the rate of budding could lead to dreadful consequences. But we're not the only people who've been working on this problem, you realize. There are outstanding scientists among the People of the Sea, just to begin with, who may be more anxious than we are for personal glorification because their traditional role has been undermined by couriers."
Tenthag clenched his mantle as the implications struck him.
"You want to start by publishing your methods of improving crops," he suggested at len
gth.
"Naturally. But the People of the Sea don't keep farms, do they—save on certain islands that they use as temporary bases when the weather's bad? Besides, we landlivers far outnumber them now."
"Is that true? I had the impression—"
"Oh, yes. We've confirmed it over and over. Harvesting what they're used to thinking of as the inexhaustible resources of the sea, they grew very numerous indeed so long as they were benefiting from the interbreeding that followed the Great Thaw. But little by little their population has dwindled, too. Had it not, would there have been a chance to set up the Couriers' Guild, or a need to do so?"
"I've heard that they no longer recruit as many junqs and briqs as formerly," Tenthag admitted.
"They aren't there. Those are life-forms almost as advanced as we ourselves, and subject to the same worldwide problem. What we must do is publish news of what we now know how to do to mounts and draftimals—because unproved transport will be imperative—and also to the creatures which our ancestors once used as food."
He uttered the concluding words softly and with reluctance. Tenthag instantly recognized the logic underlying them, but his inmost being was revolted.
"Are we to go back to the ways of savages?" he cried. "I know folk sometimes do in the grip of famine, but for scores-of-scores of years we've fed well enough from civilized resources—"
"You eat fish and wingets, don't you?"
"Well, yes, but they're as mindless as plants! I'd never kill a land-creature for food—or a porp like Flapper!"
"We may well have no choice." Gveest was abruptly stern. "We must decide between extinction—slow, but certain—and an increase in our breeding-rate. If we opt for the latter, we must make provision to save ourselves from famine due to overpopulation. Think, think! If twice as many buds appear in the next generation, those raising and catching food will just suffice to keep us all well fed—assuming, as I mentioned, better transportation. But if the figure isn't twice, but half-a-score times more ... what then?"