9. The sycamore fruit.—The seed of the sycamore is enclosed in a case which has a wing attached to it. The wing, the case, and the enclosed seed together constitute the fruit of the sycamore. The fruits occur in pairs ([Fig. 137]). Notice that a cord runs out to each fruit from the stalk on which the pair of fruits is borne. Make a drawing of a pair of fruits, then separate the fruits.
10. The sycamore seed.—Cut open a fruit. Can you see anything between the seed and the fruit-case? Would the hairy covering of the seed tend to keep it warm during the winter? Why? Why do you prefer to wear flannel in winter and linen in summer? Flannel is more fluffy than linen.
Remove the seed-coat carefully. Running down one side you will see a little curved rod. This is the radicle. Gently raise it with the point of your knife. Notice that the rest of the seed seems to consist of a green part, which is curled up. Uncoil the curls carefully. You find that they are two green leaves, fixed at the top of the radicle. These are the cotyledons. In the seed each cotyledon is first folded in two across the middle and then coiled up. Make a sketch showing the coils ([Fig. 4]). Can you see the plumule? It is just at the top of the radicle, where the cotyledons are fixed on.
Plants are living things.—One of our foremost naturalists[3] tells us that when he goes out into the woods, or into one of those fairy forests which we call fields, he finds himself welcomed by a glad company of friends, everyone with something interesting to tell. Such a feeling would be quite impossible to one who did not vividly recognise the fact that plants are alive; for it is precisely this recognition or its absence which makes the observation of the forms and habits of plants fascinating or the reverse. Let the Nature-Student, then, at the outset of his work, keep the idea of life inseparably bound up with his every thought about plants. It may at first require a little effort, but before long it will enable him to understand how the friendship of the more silent half of animate nature may form one of the great pleasures of life.
The study of seeds.—The manifestation of life is so striking, and the changes in form and size take place so rapidly, in the germination of seeds, that the study of plants cannot better be commenced than with this stage of their growth. The method has also the logical virtue of beginning at the beginning, or nearly so.
These early changes can be well observed by taking various common seeds, soaking them in water until they are soft, and then allowing them to germinate in damp sawdust, taking a few out at intervals and noting their progress. The growth of the seeds takes place more rapidly if they are kept in a warm room, but in any case some days will probably elapse before much change is noticeable in them.
During the interval of waiting, some of the seeds themselves should be carefully examined, and drawings of all the parts should be made. The drawing ought on no account to be omitted. It compels the student’s attention to details which would otherwise pass unnoticed; and a careful sketch is a much better record of an observation than any amount of description alone could be. The drawing need not be elaborate; an outline pencil-sketch to scale will usually be sufficient.
Fig. 1.—A Broad-Bean seed. A, side view; B, edge view: st. sc., stalk-scar; m, micropyle. (× ⅔.)