ONTOGENY OF MAN. 293 
cells, by the division of labour among them, and by their 
perfecting, there arises the perfect organism, the compli- 
cated composition of which excites our admiration. 
It seems to me here indispensable to draw attention 
more closely to those infinitely important and interesting 
processes which accompany ontogenesis, or the individual 
development of organisms, and especially to that of verte- 
brate animals, man included. I wish especially to recom- 
mend these exceedingly remarkable and instructive phe- 
nomena to the reader’s most careful consideration, first, 
because they are among the strongest supports of the Theory 
of Descent, and secondly, because, considering their immense 
general importance, they have hitherto been properly con- 
sidered only by a few privileged persons. 
We cannot indeed but be astonished when we consider 
the deep ignorance which still prevails, in the widest circles, 
about the facts of the individual development of man and 
organisms in general. These facts, the universal importance 
of which cannot be estimated too highly, were established, 
in their most important outlines, even more than a hundred 
years ago, in 1759, by the great German naturalist Caspar 
Friedriech Wolff, in his classical “Theoria Generationis.” 
But, just as Lamarck’s Theory of Descent, founded in 1809, 
lay dormant for half a century, and was only awakened to 
new and imperishable life in 1859, by Darwin, in like 
manner Wolff's Theory of Epigenesis remained unknown for 
nearly half a century ; and it was only after Oken, in 1806, 
had published his history of the development of the in- 
teStinal tube, and after Meckel, in 1812, had translated 
Wolff's work (written in Latin) on the same subject into 
German, that Wolff's theory of epigenesis became more gener- 
