358 THE RECAPITULATION THEORY 



and it is through the long-continued action of 

 selection, and environment that the two types 

 have heen gradually evolved. You cannot turn 

 a^ white man into a negro merely by sending 

 him__tp___live in Africa : to create a negro the 

 whole ancestral history would have to be repeated ; 

 and ITImay be that it is for the same reason 

 that the embryo must repeat or recapitulate its 

 ancestral iiistorv inl>rder to Teach the adult goal. 

 I am not sure that we can at present get much 

 further ; but the above considerations give oppor- 

 tunity for brief notice of what is perhaps the 

 most noteworthy of recent embryological papers, 

 Kleinenberg's remarkable monograph on Lopado- 

 rhynchus. 



Kleinenberg directs special attention to what is 

 known to evolutionists as the difficulty with regard 

 to the origin of new organs, which is to the effect 

 that although natural selection is competent to 

 account for any amount of modification in an 

 organ after it has attained a certain size, and 

 become of functional importance, yet that it cannot 

 account for the earliest stages in the formation of 

 an organ before it has become large enough or 

 sufficiently developed to be of real use. The 

 difficulty is a serious one ; it is carefully con- 

 sidered by Mr. Darwin, and met completely in 

 certain cases ; but as Kleinenberg correctly states, 

 no general explanation has been offered with regard 

 to such instances. 



As such general explanation Kleinenberg pro- 

 poses his theory of the development of organs 



