The concept of internal selection, of a hierarchy of controls which eliminate the consequences of harmful gene-mutations and co-ordinates the effects of useful mutations, is the missing link in orthodoxy theory between the 'atoms' of heredity and the living stream of evolution. Without that link, neither of them makes sense. There can be no doubt that random mutations do occur: they can be observed in the laboratory. There can be no doubt that Darwinian selection is a powerful force. But in between these two events, between the chemical changes in a gene and the appearance of the finished product as a newcomer on the evolutionary stage, there is a whole hierarchy of internal processes at work which impose strict limitations on the range of possible mutations and thus considerably reduce the importance of the chance factor. We might say that the monkey works at a typewriter which the manufacturers have programmed to print only syllables which exist in our language, but not nonsense syllables. If a nonsense syllable occurs, the machine will automatically erase it. To pursue the metaphor, we would have to populate the higher levels of the hierarchy with proof-readers and then editors, whose task is no longer elimination, but correction, self-repair and co-ordination-as in the example of the mutated eye.