OLD AGE AND DEATH 371 



nutritive activity. During the time that the bones are 

 becoming lighter and less capable of offering resistance, 

 the muscles become, in like proportion, lighter and weaker, 

 and with a narrowing range of action ; and the associated 

 volitional and other nerve-apparatus exhibits a correspond- 

 ing lowering of energy and force. . . . The weakening 

 of the heart and the diminished elasticity of the arteries 

 provide a proportionately feebler blood-current ; and a 

 lower digestive power and a lessened appetite provide a 

 smaller supply of fuel, enough to feed, but not enough to 

 choke the slowing fires. ... It is upon the well ordered, 

 proportionately or development ally regulated, decline in 

 the several organs that the stages which succeed to maturity 

 are safely passed, and that crown of physical glory a 

 healthy old age is attained. 



" A time comes at length when, in the course of the 

 descending developmental processes, the several parts of 

 the machine, slowly and much, though equally, weakened, 

 fail to answer to one another's call, which is also weakened, 

 when the nervous, the circulatory, and the respiratory 

 organs have not force enough to keep one another going. 

 Then the wheels stop rather than are stopped, and a develop- 

 mental or physiological death terminates the developmental 

 or physiological decay. . . . Yet, strange and paradoxical 

 as it may seem, this gradual natural decay and death, with 

 the physiological processes which bring them about, do not 

 appear to present themselves in the ordinary economy of 

 nature, but to be dependent upon the sheltering influences 

 of civilisation for the opportunity to manifest themselves, 

 and to continue their work." 



Professor Humphrey's summing up may be taken as 

 an authoritative statement of the average state of affairs 

 in human old age, and it is in no way affected by the in- 

 teresting exceptions that we all know. Thus, for instance, 



