VI PREFACE. 



is sufficient to illustrate this. To the writer another objection is that 

 the BNA strives to do away with all personal names. These, it would 

 seem, have a great value as they are indications of the history of 

 anatomical discovery and memorials of the great anatomists of the 

 past. Dorsal and ventral are used instead of the anterior and pos- 

 terior of human anatomy, while anterior indicates toward the head, 

 posterior toward the tail, these terms being readily applied to all ver- 

 tebrates, man only excepted. Cephalad and caudad, adopted by 

 some, lead to occasional peculiar phrases. The German word 

 'anlage' has been adopted bodily, and seems to call for no defense. 

 It implies the indifferent embryonic material from which a part or an 

 organ develops. 



The illustrations have been drawn or redrawn expressly for this 

 work. Some of them are original, some based on figures in special 

 papers. Practically none have ever appeared in any text-book in the 

 English language. In selecting the objects to be figured especial 

 pains has been taken to avoid the forms usually studied in our 

 laboratories, thus relieving the student of the temptation of copying 

 the figure, instead of drawing from nature. Especial thanks are due 

 to Professor C. F. W. McClure, who allowed me to draw at will from 

 the splendid collection which he has built up at Princeton. These 

 figures are indicated by the word 'Princeton' followed by the num- 

 ber of the preparation in the museum of the University. 

 TUFTS COLLEGE, MASS. 



