In winter these boxes should be kept on the hot pipes in school. The sawdust should not be allowed to get dry, neither should it be deluged with water, but kept evenly moist if possible.
Be careful to use water not colder than the temperature of the room in which the seeds are grown. Nothing checks growth more effectively than chilling with icy-cold water. It is a good plan to keep the watering-pan full of water near the hot pipes, refilling it always after use.
Seeds germinate best in the dark, but whenever the plumule shows above the sawdust, the box containing them should be placed in the light. Sufficient seeds should be sown at one time to supply a plant to each pupil once a week for at least four weeks. A number of seeds or plants should be dug up once a week and sketched by the children. Each sketch should be compared with that of the previous week, and all changes duly noted down.
The best seeds to grow are:—Broad bean, common or “large white” maize, runner bean (“Painted Lady”), French bean, kitchen pea (“Stratagem”), and white mustard.
A few seeds of white mustard should be sprinkled on a small piece of moist blotting-paper, and covered over by a small glass bell-jar or an inverted tumbler. In less than a week the root-hairs may be seen.
If hot-water pipes are available, the following seeds should be grown, as their germination is interesting:—date stones, walnuts, chestnuts, almonds, cherry stones, orange pips, seeds of cucumber and sunflower.
After maize and bean (or pea) plants have reached the height of 5 inches, they should be transferred to bottles of tap water—as described at the end of Lesson VI.—and the continuous growth sketched and noted from week to week.
POND AND DITCH HUNTING.—Make a ring of stout brass wire about 8 or 10 inches in diameter, and to this attach a bag net made of mosquito netting not more than 9 inches deep. In making the wire ring, leave attached to it about 5 inches of the twisted ends of the wire. Such a net as this can be easily carried and quickly attached to the end of a walking-stick by means of a piece of string.
The best “finds” are often made by sweeping the net under banks and among pond weeds.
FROG SPAWN.—Frog spawn is abundant in ponds and ditches everywhere in March. It should be kept immersed in as much water as possible in a large vessel, preferably of glass. Whenever the water show signs of fouling, it should be changed; but, as changing water containing tadpoles is somewhat difficult, the fewer changes the better.