Those interested in the human spine and its afflictions always welcome summaries of our present knowledge. In the initial chapters of this book, the authors lucidly summarize spine embryology, anatomy, and mechanics. An outline of pathology, biochemistry, and metabolic alterations during various stages of degenerative disk disease provides basic information which is integrated with clinical disorders of the spine. This correlation provides for disk disease a unified concept which derives partly from scientific data and, by necessity, partly from empirical observations. Excellent roentgenograms, drawings, and photographs complement the text. Clinical manifestations of cervical syndromes are adequately portrayed. Many would restrict operative indications more than do the authors, especially in patients with residual symptoms after a hyperextension injury. Two chapters on clinical features of lumbar disk disease clearly describe various syndromes and explain their pathologic significance. Some repetition in these adjacent sections indicates that the two might well be combined. Extending