224 SELECTION. Chap. XXI 



CHAPTER XXI 



selection, continued. 



NATURAL SELECTION AS AFFECTING DOMESTIC PRODUCTIONS — CHARACTERS WHICH 

 APPEAR OF TRIFLING VALUE OFTEN OF REAL IMPORTANCE — CIRCUMSTANCES 

 FAVOURABLE TO SELECTION BY MAN — FACILITY IN PREVENTING CROSSES, AND 

 THE NATURE OF THE CONDITIONS — CLOSE ATTENTION AND PERSEVERANCE INDIS- 

 PENSABLE — THE PRODUCTION OF A LARGE NUMBER OF INDIVIDUALS ESPECIALLY 

 FAVOURABLE — WHEN NO SELECTION IS APPLIED, DISTINCT RACES ARE NOT FORMED 

 HIGHLY-BRED ANIMALS LIABLE TO DEGENERATION — TENDENCY IN MAN TO 

 CARRY THE SELECTION OF EACH CHARACTER TO AN EXTREME POINT, LEADING TO 

 DIVERGENCE OF CHARACTER, RARELY TO CONVERGENCE — CHARACTERS CONTINUING 

 TO VARY IN THE SAME DIRECTION IN WHICH THEY HAVE ALREADY VARIED 

 DIVERGENCE OF CHARACTER, WITH THE EXTINCTION OF INTERMEDIATE VARIETIES, 

 LEADS TO DISTINCTNESS IN OUR DOMESTIC RACES — LIMIT TO THE POWER OF 

 SELECTION — LAPSE OF TIME IMPORTANT — MANNER IN WHICH DOMESTIC RACES 

 HAVE ORIGINATED — SUMMARY. 



Natural Selection, or the Survival of the Fittest, as affecting 

 domestic productions. — We know little on this head. But as 

 animals kept by savages have to provide their own food, 

 either entirely or to a large extent, throughout the year, it 

 can hardly be doubted that, in different countries, varieties dif- 

 fering in constitution and in various characters would succeed 

 best, and so be naturally selected. Hence perhaps it is that the 

 few domesticated animals kept by savages partake, as has been 

 remarked by more than one writer, of the wild appearance of 

 their masters, and likewise resemble natural species. Even 

 long-civilised countries, at least in the wilder parts, natu 

 selection must act on our domestic races. It is obvious tl 



al 



varieties, having very different habits, constitution, and struc- 

 ture, would succeed best on mountains and on rich lowland 

 pastures. For example, the improved Leicester sheep were 

 formerly taken to the Lammermuir Hills ; but 



o 



a 



ep-master reported that "our coarse lean pastures were 

 unequal to the task of supporting such heavy-bodied sheep ; 

 and they gradually dwindled away into less and less bulk : 





