terns yet he finds in the higher development of his ner- 

 vous system an advantage that offsets the weaknesses of 

 his constitution elsewhere. He holds his supreme place 

 by virtue only of superior and more effective control of 

 his organization. 



Behind their seeming structural differences, only one real 

 distinction can be found to separate man from the apes 

 the higher development of the brain. The erect posture, the 

 correlated modifications of skeletal and muscular struc- 

 tures, and apparently the powers of speech and reason, 

 seem to be dependent upon the enlargement of this organ, 

 which, so to speak, has pushed the face around under the 

 brain-case. Therefore he who would be 6 avOpcuTros 

 he who looks ahead must needs stand erect in order to 

 prevent his eyes from looking straight into the ground. 

 But the most careful analysis has so far failed to detect 

 any essential differences in either structural or functional 

 respects between the human brain and the corresponding 

 organs of the higher apes. In brief, then, differences in 

 degree and not in kind or category seem to distinguish 

 man from the apes as far as science goes. 



Moreover, the human body is a veritable museum of 

 rare and interesting relics of antiquity the useless ves- 

 tiges and rudiments of structures that are more developed 

 in other animals. The complete coat of hair of the embryo, 

 the disappearing thirteenth rib, the ape-like and transi- 

 tory clasping muscle of the new born infant's hand, the 

 curvature of the lower limb and the hand-like foot of the 

 embryo, these and scores of other characters are mutely 

 eloquent witnesses to the past history of change that has 

 brought man to his present place in nature. Embryology 

 gives a vast amount of additional independent testimony. 

 For like all embryo mammals and birds and reptiles, the 

 human embryo possesses gill-slits, and fish-like heart and 

 brain. Above all it begins life as a single cell. Zo- 



28 



