LUTHER BURBANK 



ties of any given orchard fruit, like the best apples, 

 or pears, or plums. 



That is to say, they may be indefinitely propa- 

 gated by division, and all the plants grown from 

 the original individual will retain the essential 

 characteristics of the original. But, like apples, 

 pears, and plums, they cannot be depended on to 

 transmit their best characteristics unvaryingly 

 from the seed. 



With the new Opuntias, as with the orchard 

 fruits and so many cultivated plants, the various 

 hereditary factors are blended in more or less 

 unstable combinations, and this unstability will be 

 revealed in the offspring grown from the seed. 



So the recognized method of propagating the 

 Opuntias is to plant a slab, and to let this serve 

 as the foundation from which roots and branches 

 will grow. The slabs that develop on each plant 

 may of course be similarly cut off and planted, so 

 that a large territory may be rapidly covered with 

 cactus plants, all precisely like the original. 



Mention was made in the preceding chapter of 

 certain cases in which an individual cactus slab 

 that was practically without spines might develop 

 other slabs that would be spiny. This could only 

 occur, however, in case the slab in question was 

 an individual variant which owed its lack of spines 

 to some local condition of altered nutrition. 



[212] 



