IX. 
‘The Development of the Individual (Ontogenesis) is a Repetition of the 
Historical Development of the Family (Phylogenesis). 
ALTHOUGH the paleontological 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 paleontological series, as well as 
with the systematic order of succession. The paral- 
lelism of the palzontological 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 adinit of no other 
choice ; either they remain uncompreliensible, or they 
