When the seeds have been evenly distributed in rows like houses along a street there comes another very important step,--the covering of the seeds. If seeds are covered too deep they will rot because of too much moisture; if the covering is too thin, the soil will dry so rapidly that the seeds will fail because of insufficient moisture. The size of the seed usually determines the amount of covering necessary. As a broad general rule, the soil covering should be about four times the thickness of the seed. Having been covered, the earth must be thoroughly watered. This must be done gently and carefully. If done with a rush, the water will wash the covering away and many of the seeds will be left bare. Whenever such an accident occurs, the seed may be pushed into the soil with a toothpick. At most times when watering, continue to apply the water until it just begins to drain through the bottom of the flat. This should be practiced even after the seeds have germinated and become growing plants. Keep the flats shaded until the plants begin to push their heads through the soil. After this time strong light should gradually be given them that the plants may not become tall and spindling, or "leggy," as gardeners say. [Illustration: _Fig. 359. Transplanted into a pot._] If the seed boxes are in a sunny or windy place, the soil may dry out too rapidly. This can be prevented by laying a newspaper over the flat when the sun strikes it. As the plantlets grow, care must be taken not to shade them too much. A PLANT KINDERGARTEN. In some plants the first leaves are called the "seed-leaves," and, like children's milk teeth, soon disappear. The next set are the true leaves. After the true leaves appear, if the plants seem crowded and uncomfortable, like three boys trying to sleep in a narrow bed, transplant them into other flats prepared similarly to the one into which the seeds were sown. You may think of this as the promotion of the young plants from the cradle to the kindergarten. Here the plants should be placed about an inch from each other, in squares. Wet the plants thoroughly before taking them up and also the soil into which they are to make their second home. After this is done, the soil should be pressed firmly about the roots, as you snuggle the bedclothes about your neck on a cold winter's night. It is entertaining practice to transplant the plants into pots, if you happen to have any florist's pots of small size. [Illustration: _Fig. 360. A soap box put to use._]