Len Marlow, the protein tank-culture technician responsible for the mushroom steaks, had wormed his way into the group and asked Pat a question. Now he was saying, "I don't dig you, Pat. It sounds like you're putting the people into the tanks instead of the vegetables!" He glanced at them, looking puzzled. "See if you two can make anything of this. It sounds medical to me." Pat leaned back and smiled, sipping a glass of hydroponic burgundy. "Wonderful stuff. You'll have to show us how to make it." Len turned back to him. "You people live off the country, right? You hunt and bring in steaks and eat them, right? Well, say I have one of those steaks right here and I want to eat it, what happens?" * * * * * "Go ahead and eat it. It just wouldn't digest. You'd stay hungry." "Why?" Len was aggrieved. "Chemical differences in the basic protoplasm of Minos. Different amino linkages, left-handed instead of right-handed molecules in the carbohydrates, things like that. Nothing will be digestible here until you are adapted chemically by a little test-tube evolution. Till then you'd starve to death on a full stomach." Pat's side of the table had been loaded with the dishes from two trays, but it was almost clear now and the dishes were stacked neatly to one side. He started on three desserts, thoughtfully tasting each in turn. "Test-tube evolution?" Max repeated. "What's that? I thought you people had no doctors." "It's a story." Pat leaned back again. "Alexander P. Mead, the head of the Mead clan, was a plant geneticist, a very determined personality and no man to argue with. He didn't want us to go through the struggle of killing off all Minos plants and putting in our own, spoiling the face of the planet and upsetting the balance of its ecology. He decided that he would adapt our genes to this planet or kill us trying. He did it all right.'" "Did which?" asked June, suddenly feeling a sourceless prickle of fear. "Adapted us to Minos. He took human cells--" * * * * * She listened intently, trying to find a reason for fear in the explanation. It would have taken many human generations to adapt to Minos by ordinary evolution, and that only at a heavy toll of death and hunger which evolution exacts. There was a shorter way: Human cells have the ability to return to their primeval condition of independence, hunting, eating and reproducing alone. Alexander P. Mead took human cells and made them into phagocytes. He put them through the hard savage school of evolution--a thousand generations of multiplication, hardship and hunger, with the alien indigestible food always present, offering its reward of plenty to the cell that reluctantly learned to absorb it.