XI.] SPECIFIC GENESIS, 



235 



CIIArTER XL 



SrECIFIC GENESIS. 



Review of the Stiitementfl and Arpuinents of Preceding Clinpters.— Ciinnilntivo Arpn- 

 ment npalnst Predonilnnnt Action of "NntiirnI Pelectlrn."— Whether nny tlilnp 

 positive fts well ns negative can ho enuneiated.— Constancy of I^wa of Nature does 

 not necessarily imply Constancy of Speeiflo Evolution.— Posslhln Kxccptionni PU- 

 Mlity of Kxifltlnff Epoch.— rroimhillty that nn Internal Cnnso of CImnjfo exists.— 

 Innate Powers must bo eonceive<l as existinf^ somewhere or other. — Pymhollsm of 

 Molecular Action under Yibmtinp Impulses.— Prof Owen's Statement. — .Statement 

 of tho Autlior'B View.— It nvoids the Difllculties wldch oppo.so "Nntunil Pelec- 

 tlon."— It harmonizes Apparently Conflicting Conceptions. — Summary and Con- 

 clusion. 



IlAvirTG now Rovorally reviewed the jirineipal biolofrical 

 facts wliicli bear upon specific manifestation, it remains to 

 sum up the results, and to endeavor to ascertain what, if 

 any thing", can be said positively^ as well as negatively, on 

 this deeply interesting' question. 



In the preceding chapters it has been contended, in the 

 first place, that no mere survival of the fittest accidental 

 and minute variations can account for the incipient stages 

 of useful structures, such as, e. g., the heads of flat-fislics, 

 the baleen of whales, vertebrate limbs, the laryngeal struct- 

 ures of the new-born kangaroo, the pedicellarino of Ecliin- 

 oderms, or for many of the facts of mimicry, and especially 

 those last touches of mimetic perfection, where an insect 

 not only mimics a leaf, but one worm-eaten and attacked 

 by fungi. 



Also, that structures like the hood of the cobra and the 

 rattle of tho rattlesnake seem to require another explana- 

 tion. 



