How Insects Help
As soon as the sun begins to warm the earth you may look out for spring flowers. If you have any damp ditches near you, you may find in March the Marsh Marigold in flower (picture, p. 30). This is a plant with hollow stems and dark green leaves shaped like a heart, and notched round the edge. It has large bright yellow flowers, which children often call "king-cups."
The yellow cup has only one set of flower-leaves. and inside it there are a great many dust-bags and seed-boxes. If you take off one of these seed-boxes and look on each side, you will find a little hollow with some honey in it.
The bees are very eager to get this honey, as it is so early in the year that there are very few plants in flower. They want too some of the pollen dust to make bee-bread for the baby-bees. The early flies too are in search of food. If you watch a bed of king-cups on a sunny day, you will see a number of bees and flies settling on the flowers.
They fly from flower to flower sipping a drop in each, and as they rub against the dust-bags, they carry the pollen-grains with them.
We saw in the last lesson that plants cannot make seeds unless the pollen grows downwards into the seed-box, and we find by experiments that they make better seeds when the pollen-grains come from another flower. So the bees do the flowers good, by carrying the pollen, in return for the honey that the plants give to them.
You are sure to find somewhere in the lanes in March a pretty little yellow flower like a star, with shining heart-shaped green leaves. It is the Lesser Celandine, and has a cup of five green sepals, and a crown of eight or ten yellow petals. Flies and bees come to it in numbers, for it has a drop of honey at the thin end of each petal, in the middle of the crown.
If you dig up a bit of this plant, you will find some white lumps growing among the roots. Each of these has a small bud at the top, and will grow into a plant if you put it into the ground.
Another flower already out in the fields is the common yellow Coltsfoot, a very tiresome weed to the farmers. It has a long creeping stem, and spreads very quickly underground. It has a flower-head, like the dandelion, made of hundreds of tiny flowers. This head grows on a fluffy stem which is covered with pink scales. The leaves do not grow till after the flowers are over.
Look carefully at the flower-head. You will find about forty tiny round flowers in the middle. They have dust-bags in them, and a large drop of honey. Round these stand about three hundred little flowers, each with a long yellow strap, and inside each of these outer flowers is a seed-box with two sticky horns. The bees and flies creep over these outer florets to suck the honey from the flowers in the middle, and on their way back they bring some pollen and leave it on the sticky horns.
And now, if you can find in the hedges the Cuckoo-pint or Arum I will show you a real trap for insects. It is a plant with a green pointed hood, and a purple club sticking up in the middle. We used to call it "Lords and Ladies," but many children call it "Parson-in-the-pulpit." In spring this plant has a very strong smell. When the flies smell it, they crawl down the purple club to look for honey.
On their way they pass a row of stiff hairs (1, p. 31) which bend down with their weight and let them pass. Then they come to a ring of red dust-bags (2) which are not yet open. Next they pass some useless seed-boxes (3) and reach at last the true seed-boxes (4) with sticky points.
Now they have come to the bottom, and they look for some honey. Alas! There is none there. Then they try to get back. But the stiff hairs will not bend upwards, and they are prisoners. They are shut in for a day or two, and then the sticky points of the seed-boxes wither, and each gives out a drop of honey. So the flies have not been cheated. At the same time the dust-flags burst, and the pollen dust falls on the flies. Then the stamens and the hairs wither away and the flies can get out again.
As they pass the withered dust-bags, they brush off any pollen-grains which remain, and have plenty on their backs to carry to another flower-trap.
You can see this for yourself if you will look for the Parson-in-the-pulpit, and choose two plants, one young one with the dust-bags full, and one old one in which they are withered.
Look for marsh marigold, lesser celandine, coltsfoot, and arum or cuckoo-pint.