4 88 BIOLOGICAL PHYSICS 



especially the hair, undergo changes of pigmentation, 

 which afford a very apparent and outstanding index to 

 the period of life reached by the individual, and, to some 

 extent, of the character of the life experience passed 

 through. Moreover, these pigmentary phenomena seem 

 to depend for causation on influences operating through 

 the neural circulatory media, chemically and physiologi- 

 cally, and represent, in sequence, the causes composing 

 ageing, synchronously with the other surface signs. 



It may further be said that baldness, so widely preva- 

 lent and conspicuous in the present age, represents a 

 failure of the inner neural circulations to reach and sustain 

 the growth of the hair bulbs and shafts, while the haemal 

 circulation not being fully utilisable for the purpose, the 

 inevitable result is the failure of the hair growth, and 

 the consequent death and disappearance of the hair 

 structures, with atrophy and attenuation of the hair 

 follicles, to the extent that no recuperative procedure is, 

 or can be, attended with other effect than disappointment 

 to those who try them. The occurrence of baldness 

 must, therefore, be anticipated, and the precipitate occur- 

 rence of down-grade changes prevented, in which case 

 there seems hope for the retention or preservation of the 

 hair, for a time at least ; but here it is necessary to 

 indicate, that preventive treatment to be successful must 

 be carried out on absolutely scientific and non-empirical 

 lines, and with a continuous determination to maintain 

 the vital activity which nature is showing signs of 

 inability to sustain, and which, in time, she will be 

 compelled to abandon, or modify, in consonance with 

 related changes as general ageing proceeds, and as the 

 process of physiological involution becomes more and 

 more complete. 



Besides the changes in pigmentation and growth 

 observable in the skin and its appendages as ageing 

 advances, a graduated series of changes is undergone by 

 its epidermic layers, more especially of the hands and 

 feet, which "tell the same tale" as we have here been 

 endeavouring to " unfold." Confining our remarks to 

 only one detail of the subject, that of the "ridging" of 

 the palmar and plantar surfaces respectively of the terminal 



