Let us watch this ambitious physicist as he enters his laboratory. He has started quite easily and has in a moment prepared some simple molecules from their elements. Now he has completed the first colloid that he will require, and is starting on his first organic synthesis. But his infinite wisdom does not give him eternity within a minute, and we notice that he is getting on more slowly. While the actual combination of the first molecules took only about a thousandth of a second, once he had the apparatus ready, the simplest colloid took about a second. The organic colloid has taken him about a minute; it seems that nature won’t work faster than that. She has her own rhythm and won’t be rushed. If we wait patiently till the end of the day our friend may have his first speck of protoplasm, and all the skill in the world would only have helped him to make more of it, not to have got any further in his game of evolution. But look at him now! He is making a hasty calculation as though he had just realized some great secret of nature, and knew that he could never create his homunculus. We look over his shoulder and read: _Estimated minimum time required by the synthetic processes of nature to attain various evolutionary stages._ Starting from the Minimum elements, to Time Simple inorganic compound 1/1000 sec. Simple colloid 1 sec. Protein 1 hour Primitive protoplasm 1 month Simplest uni-cellular organism 10 years Flagellate 1,000 years Mammal, including _Homo sapiens_ 1,000,000 years This highly speculative estimate is based on suggestive facts. A certain amount of time is necessary for two atoms to approach one another and form a molecule. The time required will be greater if many atoms have to settle down together into some special arrangement. For instance, the metal silver is normally crystalline, but if silver vapour is condensed too quickly the atoms will not have time to arrange themselves, and it is found that they pile up anyhow into an amorphous mass. Colloidal processes require even longer periods, because great clumsy molecules have to arrange themselves on the surface of the colloidal particles. In elementary forms of protoplasm the molecular patterns are still more complex, and yet more time must be necessary to get the molecules properly adjusted.