The first edition of this Atlas has been out of print for several years. The generous reception which it received and the continuing demand for copies of it suggested that a second edition might be found useful. In preparing it, we have attempted to improve the quality of the reproduction of the standard plates as well as of the other illustrations and to revise and augment the text in order to increase its usefulness to those who have occasion to consult it. All of the plates have been remaden many of them from new intermediates of the original hand-fims. Four new male standards remain unchanged, except for a new plate at age 3 years. In a number of instances a standard plate has been replaced by one made from a different hand film which shows the same stage of skeletal developpement more clearly than did the plate which was eliminated. The same rate of skeletal developpement illustrated in the previous edition has, however, been maintained....preface of W.W.G. S.I.P.