OUR FUTURE COURSE 219 



condition may well be different. Add to this the 

 possible successive incidence of different stimuli 

 and we have the assemblage of environmental 

 conditions which may be operative in nature. If 

 a heritage can be brought to an expression whose 

 latitude is beyond that of its previous state, it 

 may still be reversible through an equally slow 

 process, but it may have a different and potent 

 effect within the organism while maintained in its 

 new condition, and either it or some results of its 

 new development may respond to an environmen- 

 tal stimulus toward which it was previously inert. 

 The latter condition would make probable the 

 persistence of the character through its relation 

 to the second stimulus even after the cessation of 

 the first. Such an assumption is, of course, highly 

 speculative, but the conditions involved are un- 

 avoidable in the circumstances of life, and when 

 we take into consideration the internal environ- 

 mental factors, it is of great significance. 



Among the many attempts to demonstrate the 

 inheritance of acquired characters in the past, 

 these fundamental considerations have in no case 

 been met. It is not diflScult to find organisms, both 

 simple and complex, which respond to environ- 

 mental conditions through demonstrable func- 

 tional adjustment or through visible structural 

 change, nature of pigmentation, or habits. Leav- 

 ing out mutilation and mechanical malformation. 



