1957 Geloof en Wetenschap : Orgaan van de Christelijke vereeniging van natuur- en geneeskundigen in Nederland - pagina 209

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PETER G. BERKHOUT

reflected head is strongly developed but the straight head is very rumidentary. The plantaris muscle in man is so vestigial that only the tendon is left. Its homologue in the arm is the palmaris longus. This too is vestigial and is even absent in ten percent of the cadavers. It is interesting to note that as we go back among the primates these muscles are fully developed and only when the claws change to nails do they begin to atrophy. One of the most brilliant medical anatomists and anthropologists was the late Sir Arthur Keith (1866—1955). In his work on „Human Embryology and Morphology", p. 395, he discusses the azygous lobe of the right lung. A bud of this lobe is supposed to be present in all human beings, but in some the azygous lobe is developed. According to Keith this lobe is always well developed in all four-footed mammals. It extends between the heart and the diaphragm. But when animals assume the upright position the heart sinks down to the diaphragm and the space for the azygous lobe disappears. Hence it is vestigial in man. All the anthropoids have thirteen pairs of ribs. In the human embryo a vestige of the thirteenth rib appears which becomes fused with the transverse process of the first lumbar vertebra from which the diaphragm in man originates, p. 8. Sir Arthur Keith also wrotn a series of articles in the Britisch Medical Journal of 1923 on „Man's Posture: Its Evolution and Disorders". In these articles he states that the human embryo of six weeks has a free projecting tail of 9—12 segments. By the end of the 12th week the terminal 3 of 4 vertebrae have been absorbed, somewhat like the tail of the tadpole. Most significant of all he considers the vestiges of the chevron bones to which muscles are attached in anthropoids. He finally concludes, „We cannot explain the vestiges of chevron bones in our bodies, nor of the caudal lobe of the liver, nor of the azygous lobe of the right lung, unless we suppose that there was a pronograde stage in man's ancestry", p. 625. What happened to Eve when the Lord said that she would produce children in pain? The human pelvis is a very much distorted structure. Pronograde animals do not have by any means as much difficulty in parturition as women. Hernias, hemorrhoids, prolapses, varicose veins are some of the other prices we pay for the upright position. Embroyology always has made a great impression upon us. Why does the human embryo have to go through such intricate und yet definite forms if we were formed originally like a mannikin? And many

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