54 SEED. 



lected in preference for raising new plants, 

 from which seed is to be saved. 



When plants have been propagated for a 

 series of years by suckers alone, which are ad- 

 ventitious buds arising from the root, their power 

 of producing seed seems somewhat impaired, 

 this is the case with many herbaceous plants 

 and bulbs, but if a single seed be found by 

 which to raise a new plant, the faculty of bear- 

 ing seed becomes renewed. 



When seeds are first ripened, their embryo 

 is a mass of cellular substance, containing 

 starch, fixed carbon, or other solid matter in 

 its cavities; and in this state it will remain 

 until fitting circumstances occur to call it into 

 active life. 



These fitting circumstances are, a tempera- 

 ture above freezing point, a moist medium, 

 (earth) darkness, and exposure to air. 



It then absorbs the moisture of the medium 

 in which it lies, decomposes water from which it 

 inhales oxygen, and undergoes certain chemical 

 changes ; its vital powers cause one extremity 

 of it to ascend for the purpose of finding light, of 

 decomposing its carbonic acid, by parting with 

 its accumulated oxygen, and forming leaves and 

 branches, and the other extremity to descend for 



