X ADDITIONS AXD 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 Russian editions from the second English 

 edition, and the Swedish from the fifth English edition. 



Fifth 

 Edition. 



Sixth 



Edition. 



Page 



100 



158 

 220 



225 



230 



231 

 233 



234 



248 

 248 

 255 



268 



270 



307 

 319 



Page 

 vol. i. 



106 

 156 

 221 



227 

 233 



234 



237 



239 



254 

 254 

 262 



3DQ 



334 



vol. ii. 



9 



22 



Chief Additions and Corrections. 



Influence of fortuitous destruction on natural selection. 



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 retardation 

 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. 



Claparede on the analogical resemblance of the hair- 

 claspers of the Acaridas. 



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 portions, 

 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 incom- 

 petency 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 selec- 

 tion of useful structures. Lastly, reasons are 

 given for disbelieving in great and sudden modifi- 

 cations. Gradations of character, often accom- 

 panied 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 fertilitv of hvbrids not having: 



been acquired through natural selection condensed 



and modified. 



