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. 
Turrs COLLEGE, Mass. 
