xlv 



Evolution of Species. 



The principle of the Evolution of Species is a subject which is, 

 at the present time, attracting so great a share of the attention of 

 naturalists, as well as of the general thinking public, that it is 

 necessary here to allude to such investigations as have been made 

 with reference to it in an especial manner upon the objects of our 

 study. The question to be solved appears to me to be this : — Do 

 the "variations which exist, in a state of Nature, amongst the 

 various individuals of recognized species warrant the conclusion 

 that the species themselves are only modifications of other 

 precedent sj)ecies, which may themselves be ultimately referred 

 back to some supposed primeval type ? This field of enquiry is 

 far too vast to be more than glanced at in an Address like the 

 present, but so far as my own observations — for now more than 

 half a century, over the most extensive of all the tribes of Nature 

 — extend, I cannot come to any other conclusion than that the 

 variations alluded to above never extend beyond the genuine 

 limits of the species. I had hoped that long before this time Mr. 

 Darwin would have published his promised work on the modifi- 

 cations of species in a state of Nature, and it must be evident that 

 this will be the true crua: of his system. To afiirm that the 

 discovery of a new species, either fossil or recent, which is found 

 to be intermediate in certain portions of its structure between 

 already known and distinct forms, is a clear proof that the newly 

 discovered species is a descendant from one and a progenitor of 

 the other of such known forms, appears to me to be fallacious. 

 No entomologist, I venture to affirm, has come to the conclusion 

 that Carabus Cychrocephalus, although the intervening link 

 between Carabus and Cychrus, is a descendant from Carabus and 

 a progenitor of Cychrus, or vice versa. On the other hand, a 

 naturalist who believes in a grand and harmonious " Systema 

 Naturse," whether that be, as Linneus suggested, in the likeness 

 of a " mappa geograj)hica " or otherwise, has equal or even 

 greater right to assume that these newly-discovered species are 

 only so many hitherto unknown intervening links in the great 

 scheme of the creation. "Osculant groups" and "connecting 

 links " are terms well known to zoologists before the publication 

 of the ' Origin of Species,' with a definite meaning quite distinct 



