ADAPTABILITY. 13 



relation with any one of the forces enumerated is not alone 

 sufficient to enable a plant to perform all the functions 

 requisite for its well-being ; a plant may have a sufficient 

 supply of light and moisture, but if the temperature is not 

 favourable, life in the active stage does not predominate. 

 On the other hand, as previously stated, life is not rigid in 

 the sense of running in one narrow groove or disappearing ; 

 but rather, when placed under adverse conditions, if the 

 change is not too extreme and abrupt, a certain amount of 

 elasticity is manifested which in many instances results in 

 life becoming so adjusted as to perform its functions under 

 new conditions of environment. At this stage it may be 

 necessary to state that all the various organs possessed by a 

 plant, as hairs, scent, colour, wood, nutritious seeds, fruits, 

 etc. are developed for the use and benefit of the individual 

 producing them, and not, as imagined by some, for the 

 benefit of other forms of life. Now if we imagine a plant 

 having survived a change of conditions, we may be certain 

 that the proportion of work done by the various organs 

 cannot be exactly the same under the two sets of conditions ; 

 and if we also remember that the structure of a plant is that 

 which enables it to do the necessary amount of work with 

 the least expenditure of energy under existing conditions, 

 then under altered surroundings we should expect a change 

 of form, more or less pronounced, in responsion to the 

 relative amount of internal change, and this is what does 

 actually take place ; consequently in proportion to the 

 number of changes in the above sense a plant passes through, 

 the greater will be its divergence in structure and function 

 from the parent type. This condition of things may continue 

 until eventually the various functions of life are manifested 

 through organs so dissimilar in form from those of the 



