22 SELECTION BY MAN. |C"ap. I 



Principles of Selection anciently followed, and their Effects. 



Let us now briefly consider the steps by which domestic races 

 have been produced, either from one or from several allied species. 

 Some effect may be attributed to the direct and definite action of 

 the external conditions of life, and some to habit ; but he would be 

 a bold man who would account by such agencies for the differences 

 between a dray and race horse, a greyhound and bloodhound, a car- 

 rier and tumbler pigeon. One of the most remarkable features in 

 our domesticated races is that we see in them adaptation, not indeed 

 to the animal's or plant's own good, but to man's use or fancy. 

 Some variations useful to him have probably arisen suddenly, or by 

 one step ; many botanists, for instance, believe that the fuller's teasel, 

 with its hooks, which cannot be rivalled by any mechanical con- 

 trivance, is only a variety of the wild Dipsacus ; and this amount 

 of change may have suddenly arisen in a seedling. So it has pro- 

 bably been with the turnspit dog ; and this is known to have been 

 the case with the ancon sheep. But when we compare 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 compare the 

 game-cock, so pertinacious in battle, with other breeds so little quar- 

 relsome, 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 succes- 

 sive variations ; man adds them up in certain directions 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 hypothetical. 

 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 sub- 

 ject, and to inspect the animals. Breeders habitually speak of an 

 animal's organisation as something plastic, which they can model 



