Chap. I. CIRCUMSTANCES FAVORABLE TO SELECTION. 49 



or structure of each individual. Unless such attention be paid 

 nothinf^ can be effected. I have seen it gravely remarked, that 

 it was most fortimate that tlic strawberry began to vary just 

 when gardeners began to attend closely to this plant. No doubt 

 the strawberry had always varied since it was cultivated, but 

 the slight varieties had been neglected. As soon, however, 

 as gardeners picked out individual plants with slightly larger, 

 earlier, or better fruit, and raised seedlings from them, and 

 again })ickcd out the best seedlings and bred from them, then, 

 there appeared (aided by some crossing with distinct species) 

 those many admirable varieties of the strawberry which have 

 been raised during the last thirty or forty years. 



In the case of animals with separate sexes, facility in pre- 

 venting crosses is an important element of success in the for- 

 mation of new races — at least, in a country which is already 

 stocked with -other races. In this respect, enclosure of the 

 land plays a part. Wandering savages or the inhabitants of 

 open plains rarely possess more than one breed of the same 

 species. Pigeons can be mated for life, and this is a great 

 convenience to the fancier, for thus many races may be im- 

 proved and kept true, though mingled in the same aviary ; and 

 this circumstance must have largely favored the formation of 

 new breeds. Pigeons, I may add, can be propagated in great 

 numbers and at a very quick rate, and inferior birds may be 

 freely rejected, as when killed tliey serve for food. On the 

 other hand, cats, from their nocturnal rambling habits, cannot 

 be easily matched, and, although so much valued by women 

 and children, we hardly ever see a distinct breed kept up ; such 

 breeds as we do sometimes sec are iilmost always imported 

 from some other country. Although I do not doubt that some 

 domestic animals vary less than others, yet the rarity or ab- 

 sence of distinct l)reeds of the cat, the donkey, peacock, goose, 

 etc., may be attril)uted in main part to selection not having 

 been l)rought into play : in cats, from tlie difhculty in pairing 

 them : in donkeys, from onl}'^ a few ])oing kept by poor jieople, 

 and little attention paid to their breeding; for recently, in cer- 

 tain parts of Spain and of the United States, tliis animal has 

 been surprisingly modified and improved by careful selection : 

 in peacocks, from not being very easily reared and a large 

 stock not kejit : in geese, from being valuable only for two 

 puqioses, food and featliers, and more especially from no 

 plccisure having lieen felt in the display of distinct breeds ; but 

 the goose seems to have a singularly inflexible organization. 



