CREATION BY EVOLUTION 



Inasmuch as many phenomena of development are mere 

 adaptations to the conditions of embryonic or larval life and 

 could never have been present in adult animals, Haeckel 

 separated such characters, which he called "coenogenetic," 

 from the truly ancestral ones, which he called ' palingenetic." 

 Unfortunately there was no certain method of always dis- 

 tinuishing these two types of embryonic characters, but in 

 spite of this difficulty embryology was supposed to afford a 

 short and easy method of determining the ancestral history 

 of every group. Since every animal in its development from 

 the egg to the adult condition was believed to climb its own 

 ancestral tree, one can imagine the feverish zeal with which 

 the study of embryology was pursued. Here was a method 

 which promised to reveal more important secrets of the past 

 than would the unearthing of all the buried monuments of 

 antiquity — in fact nothing less than a complete genealogical 

 tree of all the diversified forms of life which inhabit the 

 earth. It promised to reveal not only the animal ancestry 

 of man and the line of his descent but also the method of 

 origin of his mental, social, and ethical faculties. 



Unfortunately there was no certain criterion by which the 

 palingenetic or ancestral features of development could be 

 distinguished from the coenogenetic or recently acquired 

 ones, and what one embryologist regarded as ancestral 

 another might consider a recent addition. Furthermore, 

 when there were no living or fossil animals resembling cer- 

 tain embryological forms the fancy was given free rein to 

 invent hypothetical ancestors corresponding to such forms. 



As a result of such speculations multitudes of phylogenetic 

 trees sprang up in the thin soil of embryological fact and 

 developed a capacity of branching and producing hypothetical 

 ancestors which was in inverse proportion to their hold on 

 solid ground. For a time embryology was studied chiefly 



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