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growth. In Anthropogenesis an inhibitive action appears to have gradually increased in significance, the rate of development became slower, the progress of development more retarded" (1926a, pp. 471–472). Therefore, Bolk argues in his most striking phrase:
If I wished to express the basic principle of my ideas in a somewhat strongly worded sentence, I would say that man, in his bodily development, is a primate fetus that has become sexually mature [einen zur Geschlechtsreife gelangten Primatenfetus]. (1926c, p. 8)
What a tenuous position for the crown of creation! An ape arrested in its development; holding the spark of divinity only through a chemical brake placed upon its glandular development; retaining a corporeal reminder, so to speak, of original sin—the potential of sinking again into the Tertiary abyss, should that brake ever be released: "You will note that a number of what we might call pithecoid features dwell within us in latent condition, waiting only for the falling away of the retarding forces to become active again" (1926c, p. 15). Pete, Aldous Huxley's young enthusiast, put it more pungently: "There's a kind of glandular equilibrium . . . Then a mutation comes along and knocks it sideways. You get a new equilibrium that happens to retard the developmental rate. You grow up; but you do it so slowly that you're dead before you've stopped being like your great-great-grandfather's fetus" (1939, p. 85).
Bolk's Evolutionary Theory
Bolk's notion of fetalization contains a host of elements that must clearly be rejected in the light of current knowledge. These include: (1) the division of characters into primary results of retarded development and secondary features of "merely" adaptive significance; (2) the insistence that retardation affects all essential features to the same degree in a single coordinated event; (3) the search for a cause of retardation in a simple chemical alteration of the glandular system; (4) the complete absence of any consideration for the adaptive significance of such retardation. With so much to question, we might conclude that the whole edifice is rotten to the core. But it is important to recognize that all these rejected contentions flow naturally from Bolk's view of evolution—and that this view, however untenable today, was popular and reasonable in its time.
In short, Bolk was not a Darwinian. He believed that inner factors controlled the direction of evolution by transforming entire organisms along harmonious and definite paths of vitalistic determina-