1 68 CLUES AND SUGGESTIONS CHAP. 



sistently applied to the explanation of 

 kindred facts in the structure of animals 

 in the past. 



So hostile have Darwinians generally 

 been to this interpretation of rudimentary 

 organs in adult animals, that some years 

 ago, when, in controversy with the late 

 Dr. George Romanes, I spoke of rudi- 

 mentary organs being interpretable some- 

 times " in the light of prophecy " rather 

 than in the light of history, he challenged 

 me to specify any one organ in any 

 creature which must certainly have been 

 developed long before it could have been 

 of use. I at once cited the case of the 

 electric organs of the Torpedo and of 

 some other fishes. The very high 

 specialisation of these organs, and the 

 immense complexity of their structure, 

 demonstrate that they must have passed 

 through many processes of organic de- 

 velopment before they could be used for 



