50 



THE GENESIS OF SPECIES. 



[CHAP. 



utility of these appendages is, even now, problematical. It 

 may be that they remove from the surface of the animal's 

 body foreign substances which would be prejudicial to it, 

 and which it cannot otherwise get rid of. But granting 

 this, what would be the utility of the first rudimentary 

 beginnings of such structures, and how could 

 such incipient buddings have ever preserved 

 the life of a single Echinus ? It is true that 

 on Darwinian principles the ancestral form 

 from which the sea-urchin developed was 

 different, and must not be conceived merely 

 as an Echinus devoid of pedicellarise ; but 

 this makes the difficulty none the less. It 

 is equally hard to imagine that the first 

 rudiments of such structures could have 

 been useful, to any animal from which the 

 Echinus might have been derived. More- 

 over, not even the sudden development of 

 the snapping action could have been bene- 

 ficial without the freely moveable stalk, nor 

 could the latter have been efficient without 

 the snapping jaws, yet no minute merely 

 indefinite variations could simultaneously 

 evolve these complex co-ordinations of struc- 

 ture : to deny this seems equivalent to 

 affirming a startling paradox. 



Mr. Darwin explains the appearance of 

 some structures, the utility of which is not apparent, by the 

 existence of certain " laws of correlation." By these he means 

 that certain parts or organs of the body are so related to 

 other organs or parts, that when the first are modified by the 

 action of " Natural Selection," or what not, the second are 



(Immensely 



enlarged. ) 



