Xll 



ADDITIONS AND CORRECTIONS. 



Fifth Sixth 

 Fdition. Edition. 



Chief Additions and Corrections. 



Page 

 140 

 142 



143 



152 



152 

 156 



200 



200 

 224 

 232 



235 

 267 

 283 

 308 

 322 



350 

 358 

 361 

 362 

 363 

 377 

 381 

 384 



395 

 398 



The account of the electric organ of fishes added to. 



Analogical resemblance between the eyes of Cephalopods and 

 Vertebrates. 



Claparede on the analogical resemblance of the hair-claspers 

 of the Acaridre. 



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 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. 



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 modification 

 of species, as always maintained in this work. 



The belief in the separate creation of species generally held 

 by naturalists, until a recent period. 



