EXERCISE X.

Forms of Sinuses.

The SI'NUS of a leaf is the space left between lobes. We represent here some of the most usual forms presented by Sinuses, with the terms describing them printed below the pictures.

FIG. 54.

FIG. 55.

Round, deep Sinus.

SCHEDULE SIX, DESCRIBING FIG. 55.

Parts? Blade, Petiole.

Venation? Palmate-veined

Margin? Serrate

Base? A broad, open Sinus.

Sinuses? Sharp, upper ones deep.

NOTE. It will be observed that our exercises contain none of the descriptions of plants and explanations of their growth which usually make up the text of botanies. These might be

A SES'SILE Leaf is a leaf without a petiole.
A STIPULATE Leaf is a leaf that has stipules.
A PET'IOLATE Leaf is a leaf that has a petiole.
An EXSTIP'ULATE Leaf is a leaf without stipules.

In Schedule Seven, it will be seen, we have dropped the question Parts? and put Kind? in its place. The words by which you answer this question are very long, but you can soon learn to handle them, and by-and-by you will find them much more convenient in leaf-description than it will be always to give a list of the parts.

easily given, but it would be a departure from our essential plan. The work before us-the observation of the external characters of plants-is itself extensive, and it can only be well done by making it at first our sole occupation. To observe carefully, to repeat our observations till they are familiar, and to acquire the ready and accurate use of the vocabulary of description, are the only true foundation of a knowledge of botany;

and we must be careful not to anticipate the work which belongs to a higher stage of the pupil's progress. The accounts of tissues, structures, and functions, add nothing to the understanding of plant-forms, and they afford proper subjects for future exercises in observation, to be given in a second book. What we have presented is eminently adapted to childhood, when sense-impressibility, and curiosity about appearances are strongest, and before the reflective powers are much developed.

The apparent meagreness of these pages is, therefore, intentional. They might easily have been filled with interesting reading matter about plants, but that would have opened the door to lesson-learning and reciting, which is a thing we specially wish to prevent.