8 ADDITIONS AND CORRECTIONS 



additions given in the third; and a third American edi- 

 tion has been printed from the fifth English edition. 

 The Italian is from the third, the Dutch and three 

 Russian editions from the second English edition, and 

 the Swedish from the fifth English edition. 



CaiEF Additions and Corrections. 



Intiuence of fortuitous destruction on natural selection. 



On tlie convergence of specific forms. 



Account of the Ground-Woodpeckor of La Plata modified. 



On the modification of tlie eye. 



Transitions through the acceleration or retardation of the 

 period of reproduction. 



The account of the electric organ of fishes added to. 



Analogical resemblance between the eyes of Cephalopoda 

 and Vertebrates. 

 234 265 Claparede on the analogical resemblance of the hair- 



claspers of the Acaridae. 



The probable use of the rattle to the Rattlesnake. 



Helrahollz on the imperfection of the human eye. 



The first part of this new chapter consists of portions, in 

 a much modified state, taken from chap. iv. of the former 

 editions. The latter and larger part is new, and re- 

 lates chiefly to the supposed incompetency of natural 

 selection to account for the incipient stages of useful 

 structures. There is also a discussion on the cauf^es 

 which prevent in many cases the acquisition through 

 natural selection of useful structures. Lastly, reasons 

 are given for disbelieving in great and sudden modifica- 

 tions. Gradations of character, often accompanied by 

 changes of function, are hkewise here incidentally con- 

 sidered. 

 268 359 The statement with respect to young cuckoos ejecting 



their foster-brothers confirmed. 

 270 362 On tlie cuckoo-like habits of the Molothrus, 



307 V. ij. 15 On fertile hybrid moths. 



319 29 The discussion on the fertility of hybrids not having been 



acquired through natural selection condensed and 

 modified. 

 326 33 On the causes of sterility of hybrids, added to and cor- 



rected. 



