A stem that is covered with hairs, and also one that is sticky in spots, serves to protect its flowers from an attack by ants, or by other insects that might do them harm; for these flowers, you remember, hold the golden dust which works such wonders when carried to another flower. And you recall, that, when bees go to plants for the sweet stuff from which honey is made, they carry this flower dust from blossom to blossom. But if the sweet stuff is given up to greedy insects, then this good work is not done; for the bees get disgusted, and stop visiting the plants which do not take more pains to please them. And so oftentimes the plant covers its stem with hairs or with sticky drops, so that the meddlesome little thieves cannot get up to the blossom at all. So if you pick a flower which leaves your fingers sticky, you must remember that the plant is only doing its duty in trying to please the bees. Although I have seen these plants do so many queer things that I am learning not to be surprised at their clever ways, I must own that I was a little astonished to see how anxious one of them was to save itself unnecessary trouble. There is a plant called the “amphibious knotweed.” This is a rather difficult name, I know. This word “amphibious” is applied to something that can live both in water and on land; and this plant grows sometimes in the pond or river, and sometimes on the shore. When on land, its stem is covered with the hairs which serve to keep meddlesome insects from climbing up to its pretty balls of pink flowers. In the water there is no danger of any such attack from insects; and so when it happens to grow in the pond or river, this knowing little plant does not trouble itself to clothe with hairs its stem, but leaves this quite smooth. Next summer I hope you will hunt up the amphibious knotweed, and will compare the smooth water stem with the hairy one that grows on land. [Illustration: Decoration] STEMS AND SEED LEAVES The smaller plants usually have green stems. The larger ones have brown, woody stems, such as you see in bushes and trees; for the trunk of the biggest tree in the world is nothing but a great stem. The delicate green stems die down to the ground during the cold winter. Sometimes the whole plant dies, the root below as well as the stem above ground. But often the root (or what we usually call the root) lives, and sends up a fresh stem the next year. But the woody stems live through the winter, and put out fresh leaves and branches the next spring. Without a magnifying glass, it is difficult to see of just what the green stems of the small plants are made up; and these you can pass by for the present. But if your teacher will cut across the stem of a large rose, you can see here an outer covering, _the green skin_; within this, a _ring of woody material_; and in the center of the stem, a _soft white stuff_ called “pith.”