II.] INCiriENT STRUCTURES. 73 



Tliesc remarks liave boon quoted at length bocanse tlioy 

 so greatly intensify the diflinulties brought forward in this 

 chapter. If the most favorable variations have to contend 

 vvitli sucli diflicultios, what must be thought as to the chance 

 of preservation of the slightly-displaced eye in a sole or of 

 the incipient development of baleen in a whale ? 



SUMMARY AND CONCLUSION. 



It has been here contended that a certain few facts, out 

 of many which might have been brought forward, are incon- 

 sistent with the origination of species by " Natural Selec- 

 tion " only or mainly. 



Mr. Darwin's theory requires miiuito, ind(^rmite, fortui- 

 tous variations of all parts in all directions, and he insists 

 that the sole operation of " Natural Selection " upon such 

 is suflicient to account for the great majority of organic 

 forms, with their most complicated structures, intricate 

 mutual adaptations, and delicate adjustments. 



To this conception has been opposed the difficulties 

 presented by such a structure as the form of the giraffe, 

 which ought not to have been the solitary structure it is ; 

 also the minute beginnings and the last refinements of pro- 

 tective mimicry etiually difficult or rather impossible to ac- 

 count for by " Natural Selection." Again, tlie difiiculty as 

 to the heads of flat-fishes has been insisted on, as also the 

 origin, and at the same time the constancy, of the limbs of 

 the highest animals. Reference has also been made to 

 the whalebone of whales, and to the impossibility of imder- 

 standing its origin through "Natural Selection" only; the 

 samoJis regards the infant kangaroo, with its singular defi- 

 ciency of power compensated for by rpaternal structures on 

 the one hand, to which its own breathing-organs bear direct 

 relation on the other. Again, the delicate and complex 

 pedicellari.'o of Echinoderms, with a certain process of dev^el- 

 oi)ment (through a secondary larva) found in that class, 

 4 



