200 THE MONTESSORI METHOD
He is now passing to the line, but this line does not represent for him the abstract contour of a plane figure. It is to him the path which he has so often followed with his index finger; this line is the trace of a movement. Following again the contour of the figure with his finger, the child receives the impression of actually leaving a trace, for the figure is covered by his finger and appears as he moves it. It is the eye now which guides the movement, but it must be remembered that this movement was already prepared for when the child touched the contours of the solid pieces of wood.
Third Series. We now present to the child the cards upon which the figures are drawn in black, giving him, as before, the corresponding wooden pieces. Here, he has actually passed to the line; that is, to an abstraction, yet here, too, there is the idea of the result of a movement.
This cannot be, it is true, the trace left by the finger, but, for example, that of a pencil which is guided by the hand in the same movements made before. These gRometric figures in simple outline have grown out of a gradual series of representations which were concrete to vision and touch. These representations return to the mind of the child when he performs the exercise of superimposing the corresponding wooden figures.
III. Differential Visual Perception of Colours: — Education of the Chromatic Sense
In many of our lessons on the colours, we make use of pieces of brightly-coloured stuffs, and of balls covered with wool of different colours. The didactic material for the education of the chromatic sense is the following, which I have established after a long series of tests made upon normal, children, (in the institute for deficients, I used as I