LAWS OF VARIATION 133 



structure, and, after thousands of generations, some 

 other and independent modification ; and these two 

 modifications, having been transmitted to a whole group 

 of descendants with diverse habits, would naturally be 

 thought to be correlated in some necessary manner. 

 So, again, I do not doubt that some apparent correla- 

 tions, occurring throughout whole orders, are entirely 

 due to the manner alone in which natural selection can 

 act. For instance, Alph. De Candolle has remarked 

 that winged seeds are never found in fruits which do 

 not open : I should explain the rule by the fact that 

 seeds could not gradually become winged through 

 natural selection, except in fruits which opened ; so 

 that the individual plants producing seeds which were 

 a little better fitted to be wafted further, might get an 

 advantage over those producing seed less fitted for 

 dispersal ; and this process could not possibly go on in 

 fruit which did not open. 



The elder Geoffroy and Goethe propounded, at about 

 the same period, their law of compensation or balance- 

 ment of growth ; or, as Goethe expressed it, ( in order 

 to spend on one side, nature is forced to economise on 

 the other side.' I think this holds true to a certain 

 extent with our domestic productions : if nourishment 

 flows to one part or organ in excess, it rarely flows, at 

 least in excess, to another part ; thus it is difficult to 

 get a cow to give much milk and to fatten readily. 

 The same varieties of the cabbage do not yield abundant 

 and nutritious foliage and a copious supply of oil-bearing 

 seeds. When the seeds in our fruits become atrophied, 

 the fruit itself gains largely in size and quality. In 

 our poultry, a large tuft of feathers on the head is 

 generally accompanied by a diminished comb, and a 

 large beard by diminished wattles. With species in a 

 state of nature it can hardly be maintained that the law 

 is of universal application ; but many good observers, 

 more especially botanists, believe in its truth. I will 

 not, however, here give any instances, for I see hardly 

 any way of distinguishing between the effects, on the 

 one hand, of a part being largely developed through 



