ADDITIONS AND CORRECTIONS. 



Sixth 



Edition. 



Chief Additions and Corrections. 



Tupe 

 68 

 101 

 142 

 145 

 149 



150 

 151 



153 



162 

 163 



168 



214 



215 



240 

 248 



252 

 284 

 301 

 328 

 343 



373 



384 

 385 

 387 

 401 

 405 

 409 



424 



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 Cephalopoda 

 and Vertebrates. 



Claparede on the analogical resemblance of the hair-claspers 

 of the Acaridan. 



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 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 dis- 

 believing 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 ac- 

 quired through natural selection condensed and modified. 



On the causes of sterility of hybrids, added to and corrected- 



Pyrgoma found in the chalk. 



Extinct forms serving to connect existing groups. 



On earth adhering to the feet of migratory birds. 



On the wide geographical range of a species of Galaxias, 

 a fresh- water fish. 



Discussion on analogical resemblances, enlarged and modified 



Homological structure of the feet of certain marsupial 

 animals. 



On serial homologies, corrected. 



Mr. E. Ray Lankester on morphology. 



On the asexual reproduction of Chironomus. 



On the origin of rudimentary parts, corrected. 



Recapitulation on the sterility of hybrids, corrected. 



Recapitulation on the absence of fossils beneath the Cam- 

 brian system, corrected. 



Natural selection not the exclusive agency in the modi- 

 fication of species, as always maintained in this work 



The belief in the separate creation of species general".; neld 

 by naturalists, until a recent perW, 



