There have thus been passed in review a variety of involuntary movements obtained in different ways, and with bearings upon many points of importance to the psychologist. They by no means exhaust the possibilities of research, or the deduction of conclusions in this field of study; but they may serve to illustrate how subtle and intricate are the expressions of the thoughts that lie within. That involuntary movements are by no means limited to the type here illustrated is easily shown. In the exhibitions of muscle-reading, the changes in breathing, the flushing, the tremor of the subject when the reader approaches the hiding-place, and the relative relaxation when he is on the wrong scent, serve as valuable clues; to borrow the apt expression of "hide and seek," the performer grows "hot" and "cold" with his subject. Then, too, the tentative excursions in one direction and another, to determine in which the subject follows with least resistance, present another variation of the same process. The hushed calm of the audience when success is near, the restlessness and whispering during a false scent, are equally welcome suggestions which a clever performer freely utilizes, thereby adding to the éclat of his exhibition. When a combination of numbers or of letters in a word is to be guessed, the operator passes over with the subject the several digits or the alphabet, and notes at which the tell-tale tremor or mark of excitement occurs, and so again performs the feat on the basis of the involuntary contractions that express the slight changes of attention or interest when the correct number or letter is indicated. In much the same way we unwittingly betray our feelings and emotions, our interest or distraction or ennui; the correct interpretation of these in others and their suppression in one's self form part of the artificial complexity of social intercourse. But in the line of experimental demonstration also, another form of involuntary movement has been brought forward in recent years by the investigation of Hansen and Lehmann upon "involuntary whispering." This investigation brings out the fact that many of us, when we think intently of a number, tend to innervate the mechanism appropriate to its utterance. We do not actually speak or whisper the word or sound, but we initiate the process. If one person thinks of a number,--say from one to ten, or from one to one hundred,--and the other records any number which at the same moment suggests itself to him, it may result that the proportion of correct or partially correct guesses exceeds that which chance would produce; and arguments for telepathy have been based on such results. In the series of experiments in question these "involuntary whisperings" were not severely suppressed,--much as in the automatograph tests one might determine to let the glass move if it would. It must be understood that there was no true whispering nor any movement of the speaking mechanism which a bystander could