CHAP. I.] SELECTION BY MAN. 21 



denly, or by one step ; many botanists, for instance, believe that 

 the fuller's teasel, with its hooks, which cannot be rivalled by any 

 mechanical contrivance, is only a variety of the wild Dipsacus ; 

 and this amount of change may have suddenly arisen in a seedling. 

 So it has probably been with the turnspit dog ; and this is known 

 to have been the case with the ancon sheep. But when we com- 

 pare the dray-horse and race-horse, the dromedary and camel, the 

 various breeds of sheep fitted either for cultivated land or mountain 

 pasture, with the wool of one breed good for one purpose, and that 

 of another breed for another purpose ; when we compare the many 

 breeds of dogs, each good for man in different ways ; when we com- 

 pare the game-cock, so pertinacious in battle, with other breeds so 

 little quarrelsome, with " everlasting layers " which never desire to 

 sit, and with the bantam so small and elegant ; when we compare 

 the host of agricultural, culinary, orchard, and flower-garden races 

 of plants, most useful to man at different seasons and for different 

 purposes, or so beautiful in his eyes, we must, I think, look further 

 than to mere variability. We cannot suppose that all the breeds 

 were suddenly produced as perfect and as useful as we now see 

 them ; indeed, in many cases, we know that this has not been their 

 history. The key is man's power of accumulative selection : nature 

 gives succossive variations ; man adds them up in certain direc- 

 tions useful to him. In this sense he may be said to have made 

 for himself useful breeds. 



The great power of this principle of selection is not hypotheti- 

 cal. It is certain that several of our eminent breeders have, even 

 within a single lifetime, modified to a large extent their breeds of 

 cattle and sheep. In order fully to realise what they have done, it 

 is almost necessary to read several of the many treatises devoted to 

 this subject, and to inspect the animals. Breeders habitually speak 

 of an animal's organisation as something plastic, which they can 

 model almost as they please. If I had space I could quote nume- 

 rous passages to this effect from highly competent authorities. 

 Youatt, who was probably better acquainted with the works of 

 agriculturists than almost any other individual, and who was 

 himself a very good judge of animals, speaks of the principle of 

 selection as "that which enables the agriculturist, not only to 

 modify the character of his flock, but to change it altogether. It 

 is the magician's wand, by means of which he may summon into 

 life whatever form and mould he pleases." Lord Somerville, speak- 

 ing of what breeders hare done for sheep, says : " It would seem 

 as if they had chalked out upon a wall a form perfect in itself, and 

 then had given it existence." In Saxony the importance of the 

 principle of selection in regard to merino sheep is so fully recog- 

 nised, that men follow it as a trade : the sheep are placed on a table 

 lid are studied, like a picture by a connoisseur; this is done three 



