After the trees were transplanted into the roof of the tube to replace the dead adults, the zoogloea would be taken piecemeal back to the tube and dumped into the channel. Here the jetfish would strain out part and eat part as they pumped water from the polar end of the tube to the equatorial end.

Toward the end of the day, he tried some of the zoogloea soup and managed to keep it down. A little later, he ate some cereal.

Martia insisted on spooning the food for him. There was something so feminine and tender about her solicitude that he could not protest.

"Martia," he said, "I may be wrong. There can be good will and rapport between our two kinds. Look at us. Why, if you were a real woman, I'd be in love with you.

"Of course, you may have made me sick in the first place. But if you did, it was a matter of expediency, not malice. And now you are taking care of me, your enemy. Love thy enemy. Not because you have been told you should but because you do."

She, of course, did not understand him. However, she replied in her own tongue, and it seemed to him that her voice had the same sense of sympatico.

As he fell asleep, he was thinking that perhaps Martia and he would be the two ambassadors to bring their people together in peace. After all, both of them were highly civilized, essentially pacifistic, and devoutly religious. There was such a thing as the brotherhood, not only of man, but of all sentient beings throughout the cosmos, and...

Pressure on his bladder woke him up. He opened his eyes. The ceiling and walls expanded and contracted. His wristwatch was distorted. Only by extreme effort could he focus his eyes enough to straighten the arms on his watch. The piece, designed to measure the slightly longer Martian day, indicated midnight. Groggily, he rose. He felt sure that he must have been drugged and that he would still be sleeping if the bladder pain hadn't been so sharp. If only he could take something to counteract the drug, he could carry out his plans now. But first he had to get to the toilet.

To do so, he had to pass close to Martia's bed. She did not move but lay on her back, her arms flung out and hanging over the sides of the bed, her mouth open wide.

He looked away, for it seemed indecent to watch when she was in such a position.

But something caught his eye -- a movement, a flash of light like a gleaming jewel in her mouth.

He bent over her, looked, and recoiled in horror. A head rose from between her teeth. He raised his hand to snatch at the thing but froze in the posture as he recognized the tiny pouting round mouth and little blue eyes. It was the worm.

At first, he thought Martia was dead. The thing was not coiled in her mouth. Its body disappeared into her throat.

Then he saw her chest was rising easily and that she seemed to be in no difficulty.

Forcing himself to come close to the worm, though his stomach muscles writhed and his neck muscles quivered, he put his hand close to its lips.

Warm air touched his fingers, and he heard a faint whistling. Martia was breathing through it!

Hoarsely, he said, "God!" and he shook her shoulder. He did not want to touch the worm because he was afraid that it might do something to injure her. In that moment of shock he had forgotten that he had an advantage over her, which he should use.

Martia's lids opened; her large gray-blue eyes stared blankly.

"Take it easy," he said soothingly.

She shuddered. Her lids closed, her neck arched back, and her face contorted.

He could not tell if the grimace was caused by pain or something else.

"What is this -- this monster?" he said. "Symbiote? Parasite?"

He thought of vampires, of worms creeping into one's sleeping body and there sucking blood.

Suddenly, she sat up and held out her arms to him. He seized her hands, saying, "What is it?"

Martia pulled him toward her, at the same time lifting her face to his.

Out of her open mouth shot the worm, its head pointed toward his face, its little lips formed into an O.

It was reflex, the reflex of fear that made Lane drop her hands and spring back. He had not wanted to do that, but he could not help himself.

Abruptly, Martia came wide awake. The worm flopped its full length from her mouth and fell into a heap between her legs. There it thrashed for a moment before coiling itself like a snake, its head resting on Martia's thigh, its eyes turned upward to Lane.

There was no doubt about it. Martia looked disappointed, frustrated.

Lane's knees, already weak, gave way. However, he managed to continue to his destination. When he came out, he walked as far as Martia's bed, where he had to sit down. His heart was thudding against his ribs, and he was panting hard.

He sat behind her, for he did not want to be where the worm could touch him.

Martia made motions for him to go back to his bed and they would all sleep. Evidently, he thought, she found nothing alarming in the incident.

But he knew he could not rest until he had some kind of explanation. He handed her paper and pen from the bedside table and then gestured fiercely. Martia shrugged and began sketching while Lane watched over her shoulder. By the time she had used up five sheets of paper, she had communicated her message.

His eyes were wide, and he was even paler. So -- Martia was a female. Female at least in the sense that she carried eggs -- and, at times, young -- within her.

And there was the so-called worm. So called? What could he call it? It could not be designated under one category. It was many things in one. It was a larva. It was a phallus. It was also her offspring, of her flesh and blood.

But not of her genes. It was not descended from her. She had given birth to it, yet she was not its mother. She was neither one of its mothers.

The dizziness and confusion he felt was not caused altogether by his sickness. Things were coming too fast. He was thinking furiously, trying to get this new information clear, but his thoughts kept going back and forth, getting nowhere.

"There's no reason to get upset," he told himself. "After all, the splitting of animals into two sexes is only one of the ways of reproduction tried on Earth. On Martia's planet Nature-God-has fashioned another method for the higher animals. And only He knows how many other designs for reproduction He has fashioned on how many other worlds." Nevertheless, he was upset.

This worm, no, this larva, this embryo outside its egg and its secondary mother... well, call it, once and for all, larva, because it did metamorphose later.

This particular larva was doomed to stay in its present form until it died of old age.

Unless Martia found another adult of the Eeltau.

And unless she and this other adult felt affection for each other.

Then, according to the sketch she'd drawn, Martia and her friend, or lover, would lie down or sit together. They would, as lovers do on Earth, speak to each other in endearing, flattering, and exciting terms. They would caress and kiss much as Terrestrial man and woman do, though on Earth it was not considered complimentary to call one's lover Big Mouth.

Then, unlike the Terran custom, a third would enter the union to form a highly desired and indeed indispensable and eternal triangle.

The larva, blindly, brainlessly obeying its instincts, aroused by mutual fondling by the two, would descend tail first into the throat of one of the two Eeltau. Inside the body of the lover a fleshy valve would open to admit the slim body of the larva.

Its open tip would touch the ovary of the host. The larva, like an electric eel, would release a tiny current. The hostess would go into an ecstasy, its nerves stimulate electrochemically. The ovary would release an egg no larger than a pencil dot. It would disappear into the open tip of the larva's tail, there to begin a journey up a canal toward the center of its body, urged on by the contraction of muscle and whipping of cilia.