DANIEL'S EXPERIMENTS AND CONCLUSIONS 175 



bridization by grafting, and then the preservation of the variation 

 thus secured by budding. 



Asexual hybridization, according to him, sometimes operates 

 directly upon the grafted plants, sometimes indirectly upon the 

 descendants ; sometimes it affects external characters ; sometimes 

 it causes a disjunction of previously blended characters; sometimes 

 heredity and persistence are complete; sometimes partial or lack- 

 ing; often expected results can be secured. But the most impor- 

 tant practical point is that in many cases grafting has served to 

 insure systematic improvements of plants. Emphasis must be laid 

 on his remark that when a plant is to be improved in a certain re- 

 spect, it must be grafted on a stock superior in this respect. 



222. Germplasm, the continuously living substance of 

 an organism. It is capable of reproducing both itself 

 and the somatoplasm, or body tissue, in giving rise to 

 new individuals. It is the Substance, or Essence, or 

 Life which is neither formed afresh, generation after 

 generation, nor created or developed when sexual ma- 

 turity is reached, but is present all the time as the 

 potentiality of the individual, before birth and after death, 

 as well as during that period we term "life" between 

 these two events. The somatoplasm, on the other hand, 

 has no such power. It can produce only its kind the 

 ephemeral, the perishable body or husk, which sooner or 

 later completes its life cycle, dies and disintegrates. The 

 germplasm, barring accident, is in a sense immortal. 



223. Somatoplasm, the body tissues as a whole. See 

 Germplasm (222). 



