346 REPRODUCTION IN PLANTS 



tissues with those of the plant to which it has been 

 grafted. A bud cut off and inserted in a slit through the 

 bark will grow in a similar manner. 



In all these and other vegetative methods of reproduc- 

 tion there is one common fact. A piece of the plant 

 consisting of more or fewer ordinary cells is detached to 

 continue its growth elsewhere. These cells arose through 

 ordinary mitotic cell division and so in respect to their 

 nuclei are exactly like all the other cells of the plant. No 

 reduction or segregation of any kind has occurred. What- 

 ever assortment of chromosomes the original plant has 

 in its nuclei, that identical assortment will be found in 

 the detached portion. The new plant is to all intents 

 and purposes merely a part of the old. All the navel 

 orange trees of California, now running into hundreds of 

 thousands, have been derived in this manner from two 

 original trees brought from Brazil. That they are not 

 all exactly alike and equally fruitful is due to another 

 cause which will be explained in a later chapter on 

 variation. 



