1. The Seedlings of the Broad Bean should first be examined.
(a) The radicle, observed in the seed, has given rise to the primary root, on which possibly lateral roots have begun to develop. This is an instance of a true tap root.
(b) The plumule is beginning to form the stem.
(c) The cotyledons are gradually getting smaller, for the seedling is feeding on them.
These points should be emphasised by means of the blackboard, the pupils themselves drawing the seedlings as exactly as possible, always naming each part.
2. Seedlings of Sunflower.—These the pupils should describe as far as possible by themselves. They should notice from the green colour and absence of soil on the cotyledons that they are above ground, and that there is a portion of the seedling between the cotyledons and the beginning of the root; this the teacher tells them is called the hypocotyledonary portion of the stem, and the pupils ought to be able from previous lessons to explain the word, or even to make it up for themselves.
3. Seedlings of Maize.—Here the pupils will be able to describe by themselves the endosperm and the primary root, provided that only one root has shown itself. If the lateral roots have begun to develop, the teacher must explain which are lateral and which primary, and point out the difference between the primary root of this seedling and that of the bean and sunflower. It should be noticed that there is only one cotyledon, and here the point to emphasise is, that the bean and sunflower live on the food contained in, or made by, the cotyledons; the maize on the food present in the endosperm.
The seedlings three weeks old should then be compared with those already observed, the differences in length of radicle and plumule being noted.
The observation of these seedlings will naturally suggest the subject of growth. What is growth? By judicious questioning the teacher will show that it is impossible to define it, except by its manifestations in plants and animals; it is associated with the taking in of food; then by comparing the growth of a building or rock with that of a plant and animal, it will be possible to give some idea of growth by accretion as distinct from growth by assimilation; thus the mystery of growth will be gradually approached, the teacher pointing out that growth is only possible where there is life. This should be illustrated in every possible way, e.g., growth of the body, of the mind, of a school, a nation, etc.
Lastly, the effect of environment on growth will be illustrated by the seedlings grown in different media.