76 FUNCTIONAL INERTIA 



subject. He confesses * how very difficult It is 

 to perpetuate progress, difficult to maintain any 

 natural or artificial race at its highest standard ; 

 degeneracy interferes with and ruins the work of 

 man and of nature in other words, functional in- 

 ertia swamps affectability. " Many horticulturists 

 complain that all variegated plants when grown 

 on their own grounds soon revert to the ordinary 

 type. There is an unknown influence at work 

 in those cases." Unless protoplasmic inertia be 

 postulated, it is an unknown influence ; henceforth 

 it need not be unknown. Again, we read,f " The 

 Italian hemp planted in France rapidly J reverts to 

 the small variety ; " and once more, " There is a 

 limit set both to the increase and to the decrease 

 in size of a plant. You cannot force it to become 

 much larger than its type, nor can you dwarf it 

 below a certain limit " these limits are set by 

 vegetable functional inertia. This same property 

 of course is responsible for maintaining the specific 

 character of a graft implanted on a foreign stem. 

 An interesting topic is touched upon when De 

 Varigny says : ' ' The species seems for a long time 

 to resist all inducements to variation, when all of a 

 sudden it begins to vary considerably." Into this 

 side-issue we must not be tempted to digress. 

 Vegetable protoplasm, it appears, can exhibit 

 " polarity " which may be regarded as an " after- 



* De Varigny, " Experimental Evolution/' Nature Series, pp. 75 } 

 76. (London : Macmillan, 1892.) 



f Ibid* p, 72. J In two or three years. Ibid. p. 76, 



