Shortened Feet in Pigeons
Darwin thinks it highly probable that the short feet of most breeds of pigeons are due to lessened use, though he owns that the effects of correlation with the shortened beak are more plainly shown than the effects of disuse.36 But why need the inherited effects of disuse be called in to explain an average reduction of some 5 per cent., when Darwin’s measurements show that in the breeds where long beaks are favoured the principle of correlation between these parts has lengthened the foot by 13 per cent. in spite of disuse?