"Very well. Where shall we start?"
"I have some enterprising water-plants," he said diffidently.
"We have."
It was an ambitious program. But, on the other hand, life on Earth had presumably also developed against all probabilities. Here on their planet they could provide continual intelligent guidance.
They went out into their water-plants and sensed through their miles of sensory surfaces the most favorable areas of the planet. They encouraged the water-plants to breed, cross-breed and extend. They fed fractional parts of themselves to each other, loaded certain areas with nutrient life, encouraged mobility.
Great continental areas rose and sank. Generation after generation was rapidly produced and as rapidly developed and died. The planet was littered with the remains of unsuccessful experiment. But, mainly by concentration on iron-rich diets and localizing their sight perceptions repeatedly in one particular part of their species, they produced plants which no longer responded to them. They had separate existence of their own.
At last they managed to lure repeated generations out of the water and onto land.
They had the advantage not of merely controlling the environment but of being the environment. Subject to the violence of volcanoes and the endless shifting of the planet's crust, aberrations in the plane of rotation, and rapid changes of climate, as ice mounted and retreated and heat waxed and waned, within these limits they could and did make arbitrary decisions. By withdrawing from an area, either of them could create a desert. By doubling their rate of growth in a local tributary of themselves, they could create a forest. Their descendant seeds were as much part of themselves as the original trunks. In fact, they rarely distinguished between that original growth and later developments. It came as quite a surprise to them both to find there was not much left of the first bulb clusters and the first sprawling creeper.
Once they had induced the more-or-less fishes to leave the water, progress was rapid.