PREFACE. 



The accompanying volume is intended primarily for the use of students, 

 taking a practical laboratory course in Embryology. The author's experience 

 has led him to believe that the study of carefully selected sections of embryos, 

 accompanied by directions and explanations of the significant . structures in 

 each section, offers many advantages. This conviction has determined the 

 arrangement of the book. Attention is given chiefly to such points as serve 

 to explain adult anatomical relations, to illustrate general biological principles, 

 and to afford insight into pathological processes. 



Portions of the text and many of the figures have been borrowed from the 

 author's " Human Embryology." The woodcuts in Chapter IV were made by 

 C. L. Albert Probst, of Braunschweig, after drawings by Dr. E. A. Locke. To 

 both of these artists the author is indebted for their beautiful work. Much 

 assistance has been rendered by Dr. F. T. Lewis, of the Harvard Medical School, 

 to whom special acknowledgments are due for the reconstructions of the anat- 

 omy of the pig embryo of twelve millimeters and for invaluable help in the 

 correction of the proofs. 



Many of the illustrations are from the Harvard Embryological Collection, 

 without which this work could not have been undertaken. The number of the 

 embryo and of the section is given for all such illustrations. 



The title was suggested by Dr. W. T. Porter's "A Laboratory Text-book 

 of Physiology," and is adopted with his approval. 



The author requests those who use this book to communicate to him any 

 suggestions, which their experience may lead to, for improving it, in case it 

 meets with sufficient favor to call for a new edition. 



CHARLES SEDGWICK MINOT. 



CORTINA D'AMPEZZO, August, 1902. 



