232 haeckel's anthropogenie. 



remained in obscurity till it was brought to light by Darwin, and 

 by him forced upon the attention of embryologists. " Heredity " is 

 the key- word which suffices to indicate the nature of the resemblance : 

 the human being passes through certain stages in his ontogenesis 

 because these were likewise present in his phylogenesis, i.e., among 

 the series of ancestral forms which constitute his pedigree. It is 

 evident that embryology must thus be one of the most important 

 sources from which material for the establishment of a genealogical 

 system can be taken, and Haeckel formulates a law which gives ex- 

 pression to this. " The ontogenesis of any form is a short recapitula- 

 tion of its phylogenesis." The recapitulation, however, is not com- 

 plete, nor is it always correct, for not only is the conservative 

 tendency of heredity a factor in determining certain embryological 

 stages, but adaptation to new conditions also steps in with its modi- 

 fying agency. Certain difficulties are thus placed in the way of the 

 evolutionist. These are not insurmountable, for he is by no means 

 restricted to embryology for his working material ; he has comparative 

 anatomy and palaeontology to fall back upon, and the conclusions 

 which he forms from one or other of these sciences he is enabled to 

 corroborate or to modify from a study of the evidence afforded by the 

 third. In addition to the arguments from the above-named sciences, 

 those from dysteleology (the science of rudimentary organs) are of 

 great importance, for many matters which seemed incapable of any 

 rational explanation, and were especially puzzling to the teleologist, 

 ihave had a flood of light shed upon them by the establishment of the 

 relation of ontogenesis to phylogenesis. 



These sciences are comparatively new. The former dates from the 

 appearance of 'Wolfi"s "Theoria Generationis " in 1759, the latter 

 from that of Lamarck's " Philosophie Zoologique" in 1809. 



Aristotle's treatise, " Hep} Zchwv rsviffswg" remained the sole text 

 book on the subject of ontogenesis for 2,000 years, and from his 

 writings it is evident that he had an inkling of the true doctrine . 

 of epigenesis. It was only after the Reformation that new obser- 

 vations began to be made — by Fabricius in 1600, Harvey in 1652, 

 Malpighi in 1672, and others. In the first half of the 18th century, 

 naturalists were incited to the study of classification by the appear- 

 ance of Linneeus' great work, so that little, advance was made . in 

 ontogenesis. Theories were rife, however, on the insufficient data 

 already acquired (insufficient through the imperfection of the njicro- 



