But Darwinism, though it would profit greatly could the heritability of acquired characters be proven, was especially constructed to get along with the heritability of inborn characters. To be a Darwinian it is not necessary to believe that the giraffe originated by the neck-stretching of a lot of prehistoric calves anxious to feed as high as possible upon the trees of the pasture. It is enough to believe that the calves who happened to be born with the longest necks were the most apt to survive, and that they passed their longer necks on, minus any acquired stretch, so that in each generation the accidental or unaccountable long-neck variations could begin at a higher level--and so on down, or up, to the present. The theory works very well with the giraffe. Every fractional inch of additional neck seems to have a survival value. But unfortunately for Darwin, this is not the case with all variations. Many are useless or positively harmful until their accumulation has gone on until a new and workable mechanism is formed, and it is beyond the imagination of man to devise a way in which they can have been accumulated by natural selection. Fabre, the great French naturalist, pointed out hundreds of instincts among insects which could have had no survival value unless they were complete at the start--whole chains of instincts, each link positively worthless in itself. We are forced to believe that all the links arrived on the scene simultaneously and in perfect working order. The body of man, to take another example, is--in so far as it varies from an ape’s body--a variation in the direction of weakness. If the catarrhine, old world Simians began once upon a time to have children a little more human in body than the catarrhines themselves, they at that very moment began to have weaker and shorter-armed children, less well calculated to survive in the struggle for existence. It may be argued that the half-human children survived because they had better brains. And it may be argued further that it was the deflection of energy to the brain which caused the rest of the body to shrink. This is at least imaginable. What is lacking is any positive evidence that half-human children ever arrived upon the worldly scene through the genitals of monkeys. The theory is merely a working hypothesis which works somewhat less well every day.