THE GENESIS OF FUNCTIONAL INERTIA 115 



ular affectability, and some are as clearly due to 

 molecular inertia or " molecular sluggishness " as 

 Professor Bose distinctly states.* How can stair- 

 case or " treppe " effects in living matter be better 

 described than by saying that the protoplasmic 

 inertia is being overcome more and more effectively 

 at each response until it is no longer obvious ? 

 Certainly it is molecular inertia that in the non- 

 living is responsible for the " treppe " phenomenon 

 at all. 



If then it can be so satisfactorily proved by the 

 same method that is used for living matter, that 

 non-living matter possesses both the properties of 

 molecular affectability and molecular inertia, we 

 must be prepared to attribute molecular inertia to 

 living matter, seeing that we have already recognised 

 that it possesses affectability. In other words, 

 seeing that affectability is a property not possessed 

 by living matter alone but must be attributed also 

 to the non-living, so analogously, since molecular 

 inertia is demonstrable in the non-living it is ex- 

 tremely probable that it exists also in the living. 



Fatigue in metals is now a commonplace with 

 mechanical engineers ; f they are compelled to use 

 the physiological term as best expressing their 

 meaning. Now we have seen the relationship of 

 fatigue to functional inertia, viz., that the former is 



* J. C. Bose, " Response in the Living and Non-living," pp. 104, 

 109. (Longmans, 1902.) 



t Cf. Nature, vol. Ivii. 1898, p. 58, for the microscopy of " fatigued " 

 steel. 



