delicate lavender and turned away on her side of the rock.

"Very soon now," said Pater, "you will begin feeling an irresistible urge ... to sink to the bottom, to take root there in some sheltered location which will be your lifetime site. Perhaps you even have an understanding already with some ... ah ... charming young polyp of the opposite gender, whom you would invite to share your homesite. Or, if not, you should take all the more pains to make that site as attractive as possible, in order that such a one may decide to grace it with—"

"Uh-huh," said Junior understandingly. "That's what the fellows mean when they say any of 'em'll fall for a few high-class rocks."

Pater marshaled his thoughts again. "Well, quite apart from such material considerations as selecting the right rocks, there are certain ... ah ... matters we do not ordinarily discuss."

Mater blushed a more pronounced lavender. The three maiden aunts, rooted to their boulder within easy earshot of Pater's carrying voice, put up a respectable pretense of searching one another for nonexistent water-fleas.

"No doubt," said Pater, "in the course of your harum-scarum adventurings as a normal polyp among polyps, you've noticed the ways in which the lower orders reproduce themselves; the activities of the fishes, the crustacea, the marine worms will not have escaped your attention."

"Uh-huh," said Junior, treading water.

"You will have observed that among these there takes place a good deal of ... ah ... maneuvering for position. But among intelligent, firmly rooted beings like ourselves, matters are, of course, on a less crude and direct plane. What among lesser creatures is a question of tactics belongs, for us, to the realm of strategy." Pater's tone grew confiding. "Now, Junior, once you're settled you'll realize the importance of being easy in your mind about your offspring's parentage. Remember, a niche in brine saves trying. Nothing like choosing your location well in the first place. Study the currents around your prospective site—particularly their direction and force at such crucial times as flood-tide. Try to make sure you and your future mate won't be too close down-current from anybody else's site, since in a case like that accidents can happen. You understand, Junior?"

"Uh-huh," acknowledged Junior. "That's what the fellows mean when they say don't let anybody get the drop on you."

"Well!" said Pater in flat disapproval.

"But it all seems sort of silly," said Junior stubbornly. "I'd rather just keep moving around, and not have to do all that figuring. And the ocean's full of things I haven't seen yet. I don't want to grow down!"

Mater paled with shock. Pater gave his spawn a scalding, scandalized look. "You'll learn! You can't beat Biology," he said thickly, creditably keeping his voice down. "Junior, you may go!"

Junior bobbled off, and Pater admonished Mater sternly, "We must have patience, my dear! All children pass through these larval stages...."

"Yes, dear," sighed Mater.

At long last, Junior seemed to have resigned himself to making the best of it.

With considerable exertions, hampered by his increasing bottom-heaviness, he was fetching loads of stones, seaweed and other debris to a spot downslope, and there laboring over what promised to be a fairly ambitious cairn. Judging by what they could see of it, his homesite might even prove a credit to the colony (so went Pater's thoughts) and attract a mate who would be a good catch (thus Mater mused).

Junior was still to be seen at times along the reef in company with his free-swimming friends among the other polyps, at some of whom his parents had always looked askance, fearing they were by no means well-bred. In fact, there was strong suspicion that some of them—waifs from the disreputable Shallows district in the hazardous reaches just below the tide-mark—had never been bred at all, but were products of budding, a practice