-CHAPTEE XVI 



REPRODUCTION— MODES OF VEGETATIVE REPRO- 

 DUCTION 



Reproduction is the multiplication of individuals. It is 

 brought about by the detachment of portions of the 

 parent plant, which develop directly or indirectly into 

 new plants. The portions detached may be either single 

 cells or cell-masses. In the higher, or seed-plants, with 

 which we are here concerned, two modes of reproduction 

 prevail : 



1. The vegetative mode of reprodiiction, by the detach- 

 ment of certain parts or organs from the parent-plant, 

 which parts or organs are able to grow up directly into 

 new individuals. 



2. The sexvul mode of reprodiiction, which results in the 

 formation of seed. 



There is one very important biological difference 

 between the two modes of reproduction. In the vege- 

 tative mode, since detached portions of the parent, buds, 

 shoots, etc., grow up directly into new individuals, the 

 quaUties of the parent are continued unaltered in the 

 descendants. Even the characters acquired by the parent 

 during its own life are reproduced in the offspring, gener- 

 ally without any appreciable loss in quality. In this way 

 a single plant, distinguished above its fellows by the 

 excellence or peculiarity of some quality in leaf, flower, 

 or fruit, may be multiplied indefinitely for many genera- 

 tions, the descendants repeating faithfully the characters 

 of their predecessors. Many horticultural plants are 

 sports, or freaks, characterized by the possession of some 

 unusual habit or character. This may have arisen in 

 the seed itself, as in the case of the Shirley poppy, or sud- 

 denly in the form of bud- variation, upon the adult plant — 



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