308 APPLICATION OP PRINCIPLES. 



varieties, by an application to practice of physiologi- 

 cal principles. In the last chapter has been shown 

 the importance of securing the production of seed by' 

 plants in the most healthy state possible, because a 

 robust parent is likely to afford a progeny of similar 

 habits to itself. In annuals, however, this is appa- 

 rently restrained within narrower limits than in woody 

 plants, from the great difficulty of fixing a new 

 peculiarity in the former, and the facility with which 

 it may be effected in the- latter case, by means of 

 buds, cuttings, grafts, and similar modes of propaga- 

 tion. The great object of the scientific gardener who 

 desires to improve the varieties of plants upon prin- 

 ciple will be, then, by artificial means, to bring the 

 parent from which seed is to be saved as near as pos- 

 sible to that state at which he desires the seedling to 

 arrive. 



It is well known that the abstraction of fruit and 

 flowers augments the vigour of the branches, or of the 

 parts connected with them, and that the removal 

 from the former of any part which takes up a portion 

 of the food employed in the support of the flowers in- 

 creases their efficiency. Thus those varieties of the 

 Potato, which will neither flower nor fruit otherwise, 

 may be made to do both by stopping the develope- 

 ment of tubers; and, on the other hand, the size 

 and weight of the tubers themselves are increased by 

 preventing the formation of flowers and fruit. The 

 course, then, to take, in obtaining the largest possible 

 tubers in a new variety of the Potato, would be, in 

 the first plaoe, to effect that end temporarily, but dur- 



