Darwin notes the gradations in size of the beaks of species of finches, suspects that species "are confined to different islands", "But there is not space in this work, to enter into this curious subject."
Darwin fai notar a gradación en tamaño dos peteiros das especies de pimpíns, sospeita que as especies "están confinadas en diferentes illas"... "pero non hai espazo neste traballo, para entrar neste curioso suxeito."