INERTIA AS RELATED TO HEREDITY 69 



really be only some feature latent for a long time 

 in the past history of the organism, something 

 not new, in short, but ancestrally possessed. A 

 variation arising through the genuine influence of 

 the environment on affectability may be perpetuated 

 through functional inertia, as Huxley says:* 'The 

 variation in the plant once fairly started tends to 

 become hereditary and reproduce itself." Just as 

 functional inertia may oppose the appearance of a 

 reaction (hence the phrase "once fairly started"), 

 so functional momentum will tend to perpetuate it, 

 even, it may be, in the face of disadvantageous 

 surroundings. " It has been shown," says Professor 

 Huxley, "that certain forms persist with very 

 little change from the oldest to the newest fossilif- 

 erous formations, and thus show that progressive 

 development is a contingent and not a necessary 

 result of the nature of living matter." It depends 

 on the relative degrees of intensity of possession 

 of affectability and functional inertia whether 

 " development " is fostered or the status quo 

 maintained. Spencer f speaks of "a proclivity 

 towards structural arrangement of species " ; this 

 is inertial. Huxley J puts the same idea in several 

 ways in his collected essays ; Darwinism " is 

 perfectly consistent with indefinite persistence in 

 one state," and again, Nature "always tending to 

 repeat or to return to the primitive type," and 



* T. H. Huxley, " Darwiniana : Collected Essays," vol. ii. 1902, p. 440. 



f Spencer, " Wood's Holl Lectures," 1894, p. 29. 



| " Collected Essays," vol, ii. p, 90, Ibid. p. 397. 



