II.] 



INCIPIENT STRUCTURES. 



which it cannot otherwise get rid of. But granting this, 

 what would be the utility of the first rudi- 

 mentary 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 ances- 

 tral form from which the sea-urchin developed 

 was different, and must not be conceived 

 merely as an Echinus devoid of .pedicellariaa ; 

 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. Moreover, not 

 even the sudden development of the snap- 

 ping action could have been beneficial with- 

 out the freely movable stalk, nor could the 

 latter have been efficient without the snap- 

 ping jaws, yet no minute merely indefinite 

 variations could simultaneously evolve these 

 complex coordinations of structure ; to deny 

 this seems to do no less than to affirm a start- 

 ling 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 simul- 

 taneously affected, and increase proportionally or possibly 

 so decrease. Examples of such are the hair and teeth 

 in the naked Turkish dog, the general deafness of white 

 cats with blue eyes, the relation between the presence of 

 more or less down on young birds when first hatched, and 



PEDICELLARIJ3. 



(Immensely 

 enlarged.) 



