ORGANIC EVOLUTION 69 



others are pure albinos. One of the most monstrous 

 varieties has a three-lobed tail-fin, and its eye- 

 balls, without sockets, are on the outside of its 

 head. All of our common barnyard fowls 

 turkeys, ducks, geese, and chickens are flight- 

 less, but the varieties from which the domesticated 

 forms have come all have functional wings, two of 

 these varieties crossing continents in their annual 

 migrations. 



Not only animals, but plants also, many of 

 them, have been greatly changed by man in his 

 efforts to adapt them to his uses as food, orna- 

 mentation, and the like. On the seaside cliffs of 

 Chili and Peru may still be found growing the 

 wild-potato the small, tough, bitter ancestor of 

 the mammoth Burbank, Peerless, Early Rose, 

 and the nearly two hundred other varieties of this 

 matchless tuber found in the gardens of civilised 

 man. The cabbage, kale, cauliflower, and kohl- 

 rabi are all modifications of the same wild species 

 (Brassica olc-facea), the cauliflower being the de- 

 veloped flower, kohlrabi the stalk, and kale and 

 cabbage the leaves. The peach and the almond, 

 Darwin thinks, have also come from a common 

 ancestral drupe, the peach being the developed 

 fruit, and the almond the seed. There are nearly 

 900 different varieties of apples, varying in the 

 most wonderful manner in size, colour, flavour, 

 texture, and shape, but all of ihem probably 

 derived from the little, sour, inedible Asiatic crab. 

 The many times ' double ' roses of our gardens 

 have come from the five-petalled wild-rose of the 



