THE HISTORY OF ANATOMICAL SCIENCE 299 
acceptation of the term, came into existence when 
Wolff demonstrated the fallacy of the embotte- 
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 
‘ 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® 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 egg ; 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 
® My translation of ‘Frag- moirs’ for February and May 
ments relating to Philosophical 1853. Up to that ume, 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- 
