354 THE SELF-FERTILIZATION OP PLANTS. 



crossed, and flowered before them ; they produced 

 also a far greater number of flowers which yielded 

 capsules (judging, however, from only a few) contain- 

 ing more seeds. As, in the former case, the experi- 

 ment was repeated in the same manner during the next 

 two generations, and with exactly the same result. 

 Had I not watched these plants of the Mimulus and 

 Ipomcea during their whole growth, I could not have 

 believed it possible, that a difference, apparently so 

 slight as that of the pollen being taken from the same 

 flower, and from a distinct plant growing in the same 

 small pot, could have made so wonderful a difference 

 in the growth and vigor of the plants thus produced. 

 This, under a physiological point of view, is a most 

 remarkable phenomenon." 



It is to be lamented, that such experiments, so care- 

 fully and patiently conducted, and so faithfully re- 

 ported, should add not. a jot of weight to his "great 

 law of nature;" that, such a simple idea, as the want 

 of full structural integrity, should explain the lessened 

 vigor, and the lessened fertility of self-fertilized plants ; 

 and, that the union of the different structural points, 

 of the different plants, and the return, thereby effected, 

 towards the sum of all the positive features of the 

 species ; should account for the good thence resulting. 

 All of these " most remarkable " phenomena, are 

 wholly inexplicable to Darwin. Yet, the explanation 

 is so simple and clear. The self-fertilized plants are 

 deficient in the integrity of their structural conforma- 

 tion ; whilst, when crossed, the same integrity is meas- 

 urably repaired, through each parent's supplying struc- 

 tural defects in the other, by means of the positive 

 differences which distinguish it from the other. The 



