X ADDITIONS AND CORRECTIONS. 



few of the additions given in the third; and a third 

 American edition has been printed from the fifth Eng- 

 lish edition. The Italian is from the third, the Dutch 

 and three Eussian editions from the second English 

 edition, and the Swedish from the fifth English edition. 



Fifth 

 Edition. 



Sixth 

 Edition. 



Pag. 



100 



P.g. 



vol. 1. 



106 



158 

 230 



156 



221 



225 

 330 



227 

 233 



331 

 338 



234 

 237 



234 



239 



248 

 248 

 255 



254 

 254 

 363 



268 



333 



270 



334 



307 

 319 



TOl. 11. 



9 

 22 



Chief Additions and Corrections. 



Influence of fortuitous destruction on natural se- 

 lection. 



On the convergence of specific forms. 



Account of the Ground- Woodpecker of La Plata 

 modified. 



On the modification of the eye. 



Transitions through the acceleration or retarda- 

 tion of the period of reproduction. 



The account of the electric organ of fishes added to. 



Analogical resemblance between the eyes of Cepha- 

 lopods and Vertebrates. 



ClaparSde on the analogical resemblance of the 

 hair-claspers of the Acarid». 



The probable use of the rattle to the Rattle-snake. 



Helmholtz on the imperfection of the human eye. 



The first part of this new chapter consists of por- 

 tions, in a much modified state, taken from chap, 

 iv. of the former editions. The latter and larger 

 part is new, and relates chiefly to the supposed 

 incompetency of natural selection to account 

 for the incipient stages of useful structures. 

 There is also a discussion on the causes which 

 prevent in many cases the acquisition through 

 natural selection of useful structures. Lastly, 

 reasons are given for disbelieving in great and 

 sudden modifications. Gradations of character, 

 often accompanied by changes of function, are 

 likewise here incidentally considered. 



The statement with respect to young cuckoos 

 ejecting their foster-brothers confirmed. 



On the cuckoo-like habits of the Molothrus. 



On fertile hybrid moths. 



The discussion on the fertility of hybrids not 



having been acquired through natural selection 



condensed and modified. 



