This led me to think of making modifications in my geometric insets, making use of the frame as well as of the inset I therefore made a rectangular tray, which measured 30 × 20 centimetres. This tray was painted a dark blue and was surrounded by a dark frame. It was furnished with a cover so arranged that it would contain six of the square frames with their insets. The advantage of this tray is that the forms may be changed, thus allowing us to present any combination we choose. I have a number of blank wooden squares which make it possible to present as few as two or three geometric forms at a time, the other spaces being filled in by the blanks. To this material I have added a set of white cards, 10 centimetres square. These cards form a series presenting the geometric forms in other aspects. In the _first_ of the series, the form is cut from blue paper and mounted upon the card. In the _second_ box of cards, the _contour_ of the same figures is mounted in the same blue paper, forming an outline one centimetre in width. On the _third_ set of cards the contour of the geometric form is _outlined by a blank line_. We have then the tray, the collection of small frames with their corresponding insets, and the set of the cards in three series.
[Illustration: Some of the Card Forms used in the exercises with the three series of cards.
I also designed a case containing six trays. The front of this box may be lowered when the top is raised and the trays may be drawn out as one opens the drawers of a desk. Each _drawer_ contains six of the small frames with their respective insets. In the first drawer I keep the four plain wooden squares and two frames, one containing a rhomboid, and the other a trapezoid. In the second, I have a series consisting of a square, and five rectangles of the same length, but varying in width. The third drawer contains six circles which diminish in diameter. In the fourth are six triangles, in the fifth, five polygons from a pentagon to a decagon. The sixth drawer contains six curved figures (an ellipse, an oval, etc., and a flower-like figure formed by four crossed arcs).
_Exercise with the Insets._ This exercise consists in presenting to the child the large frame or tray in which we may arrange the figures as we wish to present them. We proceed to take out the insets, mix them upon the table, and then invite the child to put them back in place. This game may be played by even the younger children and holds the attention for a long period, though not for so long a time as the exercise with the cylinders. Indeed, I have never seen a child repeat this exercise more than five or six times. The child, in fact, expends much energy upon this exercise. He must _recognise_ the form and must look at it carefully.