IX. 



The Development of the Individual (Ontogenesis) is a Repetition of the 

 Historical Development of the Family (Phylogenesis). 



Although the palseontological record is full of gaps, 

 it is nevertheless unmistakable, as even most of the 

 opponents of the doctrine of Descent are ready to admit, 

 that from the older to the more recent period, a progress 

 takes place from the lower to the higher grades of 

 organisms, which is likewise exhibited in the system of 

 the present vegetal and animal world ; and that in 

 many ways embryonic development as well as meta- 

 morphosis and heterogenesis, — in a word, individual 

 development (" Ontogenesis," Haeckel) suggests a com- 

 parison with these palaeontological series, as well as 

 with the systematic order of succession. The paral- 

 lelism of the palaeontological and the systematic series 

 is either a miracle, or it may be accounted for by the 

 doctrine of Descent. There is no other alternative. 

 And the doctrine of Descent fully bears the test ; it 

 shows how the derivation of the present organisms from 

 those previously existing rests on the transmission of 

 the characters of the progenitors to the offspring and 

 the acquisitions of the individuals. The phenomena of 

 individual development or Ontogenesis admit of no other 

 choice ; either they remain uncomprehensible, or th^y 



