"No," she corrected. "But the market for our oranges would slump without them. Here in the subtropics the big problem is water for moistening the soil. Very few of us irrigate. We have plenty of water as a rule. But we also have more than a plenty of sun. The sun sucks up the water and leaves the soil parched. In a grove like this the roots of the orange trees would suffer from it. These weeds shelter the roots from the sun, and they help keep the moisture in the ground. They are worth everything to us. Of course, in some of the fields we mulch to keep the ground damp. Milo bought a whole carload of Australian pine needles, last month at Miami. They make a splendid mulch. Wild hay is good, too. So is straw. But the pine needles are cheapest and easiest to get. The rain soaks down through them into the ground. And they keep the sun from drawing it back again. Besides, they keep down weeds in fields where we don't want weeds. See!" she ended, pointing to a new grove they were approaching. Gavin noted that here the orange tree rows were alternated with rows of strawberry plants. "That was an idea of Milo's, too," she explained. "It's 'intercrop' farming. And he's done splendidly with it so far. He thinks the eel-worm doesn't get at the berry plants as readily here as in the open, but he's not sure of that yet. He's had to plant cowpeas on one plot to get rid of it." "The experiment of intercropping orange trees with strawberries isn't new," said Brice thoughtlessly. "When the plants are as thick as he's got them here, it's liable to harm the trees in the course of time. Two rows, at most, are all you ought to plant between the tree-ranks. And that mulch over there is a regular Happy Home for crickets. If Standish isn't careful--" The girl was staring up at him in astonishment. And Gavin was aware for the first time that he had been thinking aloud. "You see," he expounded, smiling vaingloriously down at her. "I amused myself at the Miami library Saturday by browsing over a sheaf of Government plant reports. And those two solid facts stuck in my memory. Now, won't I be an invaluable aide to your brother if I can remember everything else as easily?" Still puzzled she continued to look up at him. "It's queer that a man who has just come down here should remember such a technical thing," said she. "And yesterday you warned me against letting Bobby Burns wander in the palmetto scrub, for fear of rattlesnakes. I--" "That deep mystery is also easy to solve," he said. "In the smoker on the way South several men were telling how they had lost valuable hunting dogs, hereabouts from rattlesnakes. I like Bobby Burns. So I passed along the warning. What are those queer trees?" he asked shifting the dangerous subject. "I mean the ones that look like a mixture of horse-chestnut and--"