10 Plant-Breeding 



with these qualities, so that he may synthetically put 

 many units together by crossing and produce new varieties 

 almost at will. 



Differences between plants and animals with regard to 

 general association of parts and their methods of reproduction. 

 - Unit-characters are nature's blocks, which she uses to 

 build up plants and animals into various shapes for dif- 

 ferent purposes. These combinations of units when 

 added together in proper extent and proportion consti- 

 tute the plant and animal as we know it, the ultimate 

 living and working organism, with power of growth and 

 reproduction. 



In looking for the ultimate working unit, individuality or 

 personality in nature, we must make a broad distinction 

 between the animal and the plant. Every higher animal 

 is itself a working unit ; it is one. It has a more or less 

 definite span of life, and every part and organ contributes 

 a certain indispensable part to the life and personality 

 of the organism. No part is capable of propagating itself 

 independently of the sex-organs of the animal, nor is it 

 capable of developing sex-organs of its own. If any part 

 is removed, the animal is maimed and perhaps it dies. 

 The plant, on the contrary, has no definite or distinct 

 autonomy. Most plants live an indefinite existence, 

 dependent very closely upon the immediate conditions in 

 which they grow. Every part or branch of the plant lives 

 largely for itself, it is capable of propagating and multi- 

 plying itself when removed from the parent or the colony 

 of branches of which it is a member, and it develops sex- 

 organs and other individual features of its own. If any 

 branch is removed, the tree or plant does not necessarily 



