162 



THE HUMAN MOTOR 



All the subjects are of the male sex and aged from 30 years to 

 a few weeks. In old men between 69 and 84 years old the average 

 expenditure is 28 Calories per kilogramme, or 910 Calories per 

 square metre of body surface, f 1 ) In the female sex the expendi- 

 ture is generally 96% of that of man, for equal age and weight. ( 2 ) 



(M Sonden (Skand. Archiv. f. Physiol., vol. xi. p. 60, 1910). 



(*) Magnus-Levy and Falk (loc. cit.) ; Sonden and Tiegerstedt (loc. cit.). 



() Magnus Levy et Falk (Arch. f. Anat. un Phys., Suppl., p. 314, 1899). 



( 



() Bulletin, No. 136, p. 148, 1903. 



( 5 ) Rubner (Zeitsch. f. Biol., vol. xxi., p. 393, 1885) ; J. Amar, Le Rend*- 



ment, etc. 



