CHAPTER TV. 



GERMINATION AND THE GROWTH 

 OF PLANTS 



GERMINATION 



Germination is the awakening of the dormant embryo. Its imme- 

 diate subsequent continuation is dependent upon available nutriment 

 contained in the seed._ 



THE CONDITIONS OF GERMINATION ARE 



A. VITALITY. 



B. MOISTURE. 



C. PROPER TEMPERATURE.' 



D. OXYGEN. 



Take away any one of these first four factors and life will not 

 awaken from its slumber. The successful storage of grains is depend- 

 ent upon the elimination ol as many of these favorable conditions as 

 possible. The exclusion of oxygen is a physical impossibility, while 

 the regulation of temperature is limited, but by preventing the access 

 of moisture to stored seeds, germination is prevented. 



VITALITY. The vital principle in a live seed is known only by 

 its effects. The organic life evidenced by germination is a phenom- 

 enon due to the presence of living cells in the embryo of the matured 

 seed. 



Kernels which have been subjected to continued freezing or to 

 excessively high temperatures have this life extinguished. Embryos 

 which are not full of water are not so suddenly or injuriously affected 

 by these extremes. The cells of a swollen plumule or radicle are de- 

 stroyed when the temperature is lowered below freezing. 



By experimentation, De Candolle was able to germinate seeds of 

 a few species after a storage of fifteen years. Other plants require 

 immediate favorable environment or the vitality of the seeds is weak- 

 ened or lost. Seeds of Mountain Potentilla were known to germinate 

 at Meriden, New Hampshire, when 60 years old. 



