A great many experiments have been made upon different types of animals to determine how long it would take them to learn to secure their food by going through an unusual “stunt” or travelling over a circuitous route. Mice have been taught, for example, to travel a long distance and through complicated mazes to secure their food, which is in such cases usually placed at the centre of the maze. The effectiveness of learning to thread a maze as a test of the intellectual capacity of the lower animals is probably not superior to the effectiveness of the same sort of learning as a measure of the intelligence of human beings. It is not possible, however, to include in a book the long passageways and blind alleys which would necessarily have to be built out of pretty substantial material in order to keep men from breaking over its sides, but the idea has so far as possible been carried out in the tests which follow. It is quite certain that the ability to trace through a printed maze with a pencil is not equal to the ability to walk through a specially constructed maze of steel, but it is as near the same problem as can be arranged on paper and printed in quantity. The arrangement of mazes in this member of the Mentimeter family is such that the number of mazes successfully threaded is a distinct indication of the _complexity_ of maze which the individual can successfully negotiate. The test is intended to measure the ability of any individual whether he can read or understand the English language or not. If the two examples shown on the title page are presented on a blackboard, or other large surface, the test may very easily be given as a group test by a skilful examiner, although the directions which follow are prepared for the examination of one individual at a time. _Directions for Giving the Test._ The examiner should be seated at a table at the right side of the candidate to be examined. He should first of all secure the information regarding the candidate’s name, age, and other important items, and should then exhibit the mazes which appear inside the booklet, pointing from one to the other in the first half dozen. Not more than thirty seconds should be allowed for this part of the instruction. Turning back to the title page the examiner should point to the first example, pointing first at the entrance and then to the exit. By a motion at each of these two cardinal points, made in the direction in which the arrow points, he should make it clear that the idea is to move in the direction indicated by the arrows. He should then trace his way fairly slowly from the entrance to the exit. [Illustration: Show by a line how you would pass through the drawings below without touching any line]