The essential idea in this book on stuttering is that the stutterer is one who does not clearly formulate to himself what he wishes to say. The authors call this "insuffisance linguo-speculative." Heredity may be a factor in this lack, but emotional difficulties in the family and an attempt to learn a second language before the child is sufficiently familiar with his own have seemed to be causal factors in many of the cases cited. Respiratory and motor difficulties associated with stuttering are thought to be due to the emotional upset occasioned by the inability of the subject to express himself. The book is simply written, and many case reports are given.