“The thorns also prevent the buds from being knocked off by anything rubbing against the hawthorn hedge. You will notice that each thorn is very much longer than the buds beside it. These thorns can give a very cruel prick, as every boy knows who has tried to cut a twig from the hawthorn hedge. “By and by we shall see that there are many plants which arm themselves against animals in this way.” Exercises on Lesson III. 1. Take in twigs with buds on them in December. Place them in water, and watch them from day to day. 2. Select one bud, and make a drawing of it every third day from the time it begins to open. Keep your drawings. 3. How are buds protected? (1) from cold; (2) from animals. 4. What causes the “horse-shoe” marks on horse-chestnut twigs? 5. Make a drawing of a small beech twig, showing buds and leaf-scars. IV.—A BABY PLANT. “To-day,” said Uncle George, “we are going to try to find out something about seeds.” And he placed upon the table a saucerful of beans which had been soaking in water for two days. “First let us look at the seeds as they are when we get them from the shop,” he said, laying a handful of hard, wrinkled beans upon the table. “They are as hard as stones, and very much smaller than those we soaked,” said Frank. “Yes, that is one thing we have learned about them already. Seeds take in water and swell greatly.” As he spoke, Uncle George gave Frank, Tom, and Dolly each a small knife and a needle mounted in a handle. He then laid a small magnifying glass on the table. “Take a soaked bean and look at it well,” he said. “First we will look at the outside of it, then we will see what it has inside.” “My bean is covered all over with a smooth skin,” said Dolly. “And there is a long black mark on one side of it,” Tom added. “Come on, Frank,” said his uncle, “haven’t you got something to say.” “It is sort of kidney-shaped,” said Frank. “Nothing more?” Frank shook his head. “Squeeze it,” said Uncle George, “and tell me what you see.” “Oh, there is water oozing out of a little hole at the end of the black mark,” said Frank. “That shows us that the seed is not quite covered by its skin,” said their uncle. “That little hole is there to allow a tiny root to grow out.