and varied that endless experiments can be made; it is so simple and uniform that the results of one experiment may be compared directly with the results of another; it may be drawn from any language, and so may be used in the laboratories of any country. Moreover, it is absolutely under control; it is just the kind of material that we need when we are tied down to strict and accurate method; we can vary at will the manner of presentation to the learner, the number of syllables in a series, the rate at which they follow one another, and so on; and the report required from the learner himself is easy and natural; there are no long descriptive phrases; he has only to say or to write the syllables he has learned. Lastly, _we may proceed from experiments with this meaningless material to experiments with real words_, words that mean; and we may hope in that way to pass beyond the bare essentials of the brain’s associative function, and to get a clue to the complex interplay of associative tendencies in real life. All in all, it is not too much to say that Ebbinghaus’ recourse to meaningless syllables, as means to the study of associative tendencies, marks the most considerable advance, in this chapter of the psychological system, since the time of Aristotle. § 33. =The Establishment of Associative Tendencies.=—The use of =meaningless syllables= has brought with it a whole armoury of technical methods for the study of the associative tendencies. We have here no space to treat of these methods in detail; fortunately, the results that we shall mention speak for themselves; and it may be added that all the methods of experiment are, in principle, changes rung upon one simple model, in which the observer sits down before a series of syllables, reads them through, so-many times over, in a state of attention, and then, either immediately or after an interval of time, repeats them ‘from memory.’ We proceed, then, to answer the question: How are associative tendencies established in the brain?