THE PROPAGATION OF PLANTS I'VA 



riety from seeds ; hut most tViiits and trees and 

 shrubs do not, and in sucli eases recourse 

 is had to bud jjropagation, as layers, cuttings, 

 jrrafts. 



-. Sci'dacje, or /'ropaf/dtioN hi/ Seeds 

 ■J'/, h'l i/iiisif> s nf (jtrnniiiition 



"Jib. in order that seeds shall pM-niinate, the 

 seeds tlifmsclvt^s nnist be vialtle (or "good"). 

 Vialtiiily dt'pt'uds ui>nii (n) tlif maturity of the 

 seeds, (/>) fr»»shnt'ss, — tliey shall not have lost 

 th«Mr vitality throuirh ag*', — (') the vigor and 

 geinM-al ht»althfuln»'ss i^i the plant which bore 

 the seeds, {d) jimpri- conditions of storage. 



217. {h) TIjc length of time during which 

 see<ls retain their vitality varies with the kind of 

 plant and with the con<iitions under which the 

 seeds were gi-own. That is, there is a normal 

 vitality and an incidental vitality. Most seeds 

 germinate best when not m()n' than one or two 

 years old, but n'taiii stiong vitality three or 

 four years ; but some seeds, notably those of 

 onions and parsnips, are usually not safe after 

 a year old. 



■_Ms. In order that s»'cds shall germinate, 

 they nnisi also have projM'r surrounding con- 

 ditions: niuisture, free oxygen (uir;, warmth. 



