PLANNING A NEW PLANT 197 



It will be obvious, then, that I am not prepar- 

 ing to make bricks without straw and am count- 

 ing well the materials with which I must work, 

 just as the architect from the first stroke of his 

 pencil bears in mind the materials of the future 

 cathedral. 



We do not imagine that an apple tree can be 

 produced from cherry trees, any more than the 

 architect assumes that he can build a marble 

 cathedral out of bricks; well knowing that there 

 are sharply defined hereditary limitations be- 

 yond which the cherry cannot be made to go 

 within any such period of time as that limiting 

 the experiment. 



In other words, I do not ask the impossible, 

 although it has often seemed to some of my less 

 intelligent critics that I have asked the highly im- 

 probable. 



But the results attained are in themselves very 

 sufficient answer to these critics. If my vision 

 has in some cases been the clearer, it is merely 

 that my knowledge of plant life, drawn from the 

 school of experience, has been wider. 



To the uninitiated observer it may have seemed 

 that I set no limits to the transformations at- 

 tempted. In reality, my plan has always from 

 the outset recognized most definite limits al- 

 though often enough the limits as conceived were 



