EXPERIMENTAL EVOLUTION LECT. 



than those of the left side, as H. Milne-Edwards 

 clearly recognized in his investigation on animals, and 

 such differences certainly obtain in man, as direct 

 experiments have shown. And such differences are 

 to be met not only between man and woman, between 

 one side and another, but also between one part and 

 another, lime-salts being more abundant in the thigh- 

 bone than in the arm, &c. 



If we turn to the chemistry of the blood, the same 

 facts appear. Quetelet has analyzed the salts which are 

 contained in this fluid, and has seen that the differ- 

 ences arc as follows : 



Man. Woman 



At one year 14/2 13-3 



At ten years 37-1 34-4 



At thirty years 98*9 78-4 



There is more iron in male than in female blood 

 (Boussingault) ; there arc also more salts in male than 

 in female, more in the right thigh of the duck than in 

 the left one ; there are more red blood-corpuscles in 

 man than in woman (142 against 127, after Becquerel 

 and Rodier, or 4*5 against 3*5, after Malassez), and 

 so on ; and all these minute or important differences 

 in anatomical or chemical structure are accompanied by 

 more or less important variations in physiology. Of 

 these differences I shall give only one instance : it 

 is admitted in forensic medicine that when man and 



