4 2 ^ Conclusion. 



Chap. XV. 



to be capable of definition ; and if definable, whether the differences 

 be sufficiently important to deserve a specific name. This latter 

 point will become a far more essential consideration than it is at 

 present; for differences, however slight, between any two forms 

 if not blended by intermediate gradations, are looked at by most 

 naturalists as sufficient to raise both forms to the rank of species. 



Hereafter we shall be compelled to acknowledge that the only 

 distinction between species and well-marked varieties is, that the 

 latter are known, or believed, to be connected at the present day by 

 intermediate gradations, whereas species were formerly thus con- 

 nected. Hence, without rejecting the consideration of the present 

 existence of intermediate gradations between any two forms, we shall 

 be led to weigh more carefully and to value higher the actual 

 amount of difference between them. It is quite possible that forms 

 now generally acknowledged to be merely varieties may hereafter 

 be thought worthy of specific names ; and in this case scientific and 

 common language will come into accordance. In short, we shall 

 have to treat species in the same manner as those naturalists treat 

 genera, who admit that genera are merely artificial combinations 

 made for convenience. This may not be a cheering prospect ; but 

 we shall at least be freed from the vain search for the undiscovered 

 and undiscoverable essence of the term species. 



The other and more general departments of natural history will 

 rise greatly in interest. The terms used by naturalists, of affinity, 

 relationship, community of type, paternity, morphology, adaptive 

 characters, rudimentary and aborted organs, &c, will cease to be 

 metaphorical, and will have a plain signification. When we no 

 longer look at an organic being as a savage looks at a ship, as some- 

 thing wholly beyond his comprehension; when we regard every 

 production of nature as one which has had a long history ; when we 

 contemplate every complex structure and instinct as the summing 

 up of many contrivances, each useful to the possessor, in the same 

 way as any great mechanical invention is the summing up of the 

 labour, the experience, the reason, and even the blunders of nume- 

 rous workmen ; when we thus view each organic being, how far 

 more interesting, — I speak from experience, — does the study of 

 natural history become ! 



A grand and almost untrodden field of inquiry will be opened, on 

 the causes and laws of variation, on correlation, on the effects of use 

 and disuse, on the direct action of external conditions, and so forth. 

 The study of domestic productions will rise immensely in value. A 

 new variety raised by man will be a more important and interesting 

 subject for study than one more species added to the infinitude of 



