52 FUNCTIONAL INERTIA 



metabolic rhythm. The stimuli changed quantita- 

 tively and qualitatively, but the metabolism held on 

 its own perverted way, expressed itself in its own 

 unrelated independent periodicity this is functional 

 inertia. 



Peculiarities of behaviour, whether in cells or in 

 individuals, are not brought out until some small 

 thing goes wrong the slight departure from the 

 normal metabolism (probably of purins) is sufficient 

 to bring out in these cases the presence of a deep- 

 seated rhythm. " Life is characteristically rhythmic," 

 says Vaschide.* 



The cases of established habits liable to become 

 perpetuated by functional inertia are very numerous : 

 one example may be given : nurses who have been 

 on night-duty on being changed to day-duty, often 

 have sleeplessness, | i.e., nocturnal wakefulness has 

 become a habit and is maintained under inappropriate 

 circumstances. Professor Gaule, for instance, holds 

 that muscle is subject to periodic variations in its 

 rate of growth.]: 



In his exceedingly interesting analysis of the 

 central nervous system, Dr. Mercier, ever and anon, 

 uses the concept, and sometimes, as we shall see, 

 the term " inertia" : writing of excessive katabolic 

 effects in nerve-cells, he says, "This decomposition 

 (katabolism) is in normal organisms prevented by the 



* Vaschide, Comp. Rend., vol. cxxxv. 1902, pp. 752-754. 



| Bradbury, Allbutt's " System of Medicine," vol. vii. p. 748. 



J Gaule, Nature, vol. lii 1895, p. 555. 



Mercier, " Sanity and Insanity," Contemp. Science Series, p. 182. 



