i 4 AGE, GROWTH, AND DEATH 



to the reduction in size of the single fibres. The 

 muscle has actually lost ; it is inferior, physiologic- 

 ally speaking, to what it was before. You remem- 

 ber how melancholy Jacques reminded us of this fact 

 in speaking of the hose " a world too wide for his 

 shrunk shank." His saying is justified by the loss of 

 the muscles in volume and strength. The same phe- 

 nomenon of atrophy shows itself in the digestive 

 organs. Those minute structures in the wall of the 

 stomach by which the digestive juice is produced 

 undergo a partial atrophy, in consequence of which 

 they are less able to act ; they are not so well organ- 

 ised, therefore not so efficient as in earlier stages. 

 The lungs become stiffened ; the walls which divide 

 off an air cavity from the neighbouring air cavities 

 do not remain so thin as in youth, but become thick- 

 ened and hardened, and the vital capacity of the 

 lungs, that is to say the capacity of the lungs to take 

 in and hold air, is by so much lessened. The heart 

 it seems curious at first is in the old always en- 

 larged ; but this does not represent a gain in real 

 power. On the contrary, if we study carefully the 

 condition of the circulation of the blood in the old, 

 we find that the walls of the large blood-vessels 

 which carry the blood from the heart and distribute 

 it over all parts of the body vessels which we call 

 arteries have lost the elastic quality which is proper 

 to them and by which they respond favourably to the 

 pumping action of the heart. Instead they have be- 

 come hard and stiff. We call this by a Greek term 



