go 



EVOLUTION, GENETICS, AND EUGENICS 



poid apes continue to present the rudimentary vestiges of a tail in a 

 few caudal vertebrae below the integuments, we might well expect to 

 find a similar state of matters in the case of man. And this is just 



Fig. 15. — Diagrammatic outline of the human embryo when about seven 

 weeks old, showing the relations of the limbs and tail to the trunk. {After Allen 

 Thompson.) r, the radial, and 71, the ulnar, border of the hand and forearm; 

 /, the tibial, and/ the fibular, border of the foot and lower leg; an, ear; u , spinal 

 cord; «, umbiUcal cord; J, bronchial gill slits; c, tail. {From Romanes.) 



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doccyx:. 



Fig. 16. — Front and back view of adult human sacrum, showing abnormal 

 persistence of vestigial tail muscles. {From Romanes.) 



what we do find, as a glance at these two comparative illustrations 

 will show (Fig. 14). Moreover, during embryonic life, both of the 

 anthropoid apes and of man, the tail much more closely resembles 



