THE HISTORY OF ANATOMICAL SCIENCE 299 



acceptation of the term, came into existence when 

 Wolff demonstrated the fallacy of the emboite- 

 ment theory ; and also proved that the leaves, the 

 petals, the stamens, and so forth, of flowering 

 plants do, as a matter of fact, start from one and 

 the same primary form in the bud and become 

 differentiated as they grow. It was thus that, 

 thirty years before Goethe saw how the relations of 

 living forms could be ideally represented, Wolff 

 proved what they in fact are. In quite another 

 sense from that of Goethe's reply to Schiller, the 

 embryologist showed cause for the belief that 

 1 unity of organisation ' is not an idea, but a fact. 

 The study of the actual process of individual 

 evolution, thus put on a firm foundation, steadily 

 advanced, until Von Baer 6 arrived at the great 

 generalisation that all such evolution is a progress 

 from relative^ simplicity to relative complexity ; 

 in other words, that it is the gradual differentiation 

 of a relatively homogeneous living substance repre- 

 sented by the ^gg ; that, in so far as all indivi- 

 dual living beings start from ova of essentially 

 similar simplicity of structure, and as the earliest 

 steps of their development or evolution are 

 similar, the fundamental unity of their organisa- 

 tion is a fact ; on the other hand, that, in so 



6 My translation of ' Frag- moirs ' for February and May 



ments relating to Philosophical 1853. Up to that time, I be- 



Zoology, selected from the lieve, Von Baer's ideas were 



Works of K. E. Von Baer,' was hardly known outside Germany, 

 published in ' Scientific Me- 



