IX. 



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

 Historical Development of the Family (Phylogenesis)I 



Although the palseontological record is full of gaps, 

 it is nevertheless unmistakable, as even most of the op- 

 ponents 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 or- 

 ganisms, which is likewise exhibited in the system of 

 the present vegetal and animal world; and that in many 

 ways embryonic development as well as metamorphosis 

 and heterogenesis, — in a word, individual development 

 (" Ontogenesis,'' Haeckel) suggests a comparison with 

 these palseontological series, as well as with the sys- 

 tematic order of succession. The parallelism of the 

 palseontological and the systematic series is either a mir- 

 acle, or it may be accounted for by the doctrine of 

 Descent. There is no other alternative. And the doc- 

 trine of Descent fully bears the test; it shows how the 

 derivation of the present organisms from those pre- 

 viously existing rests on the transmission of the char- 

 acters of the progenitors to the oiTspring and the ac- 

 quisitions of the individuals. The phenomena of indi- 

 vidual development or Ontogenesis admit of no other 

 choice; either they remain incomprehensive, or they 



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