THE SEED. 67 



this needs some explanation. In distinct species, this will 

 be true ; but the seeds of varieties that have been pro- 

 duced by culture and hybridizing, seldom, or never, repro- 

 duce exactly their like, hence the necessity for the various 

 artificial methods of multiplication, such as grafting, bud- 

 ding, layering, etc. It is to these operations that we are 

 indebted for the preservation of varieties that were origi- 

 nated, hundreds of years ago. 



Germination. Heat arid moisture, air, and the exclu- 

 sion of light, are all necessary to the healthy and perfect 

 germination of seeds. It may be well to consider, briefly, 

 the part which each of these has to perform. 



1st. Moisture. If seeds are sown in a time when 

 the ground is parched, they will show no signs of germi- 

 nation until it is, in some way or other, moistened. The 

 quantity of moisture necessary to a seed depends on the 

 nature of its covering, and its size. A small seed, with 

 a thin covering, will vegetate much sooner, and with less 

 moisture, than a large seed, with a hard, bony covering. 

 The moisture must, in the firs j place, soften the covering, 

 penetrate to the mealy part of the seed, and prepare it 

 for the chemical changes necessary to convert it into food 

 for the embryo plant. If apple or pear seeds be kept in 

 a dry, warm room all winter, they will not be likely to 

 vegetate the succeeding spring, but if sown, will probably 

 lie in the ground all summer, and possibly germinate the 

 spring following. If cherry seeds are kept dry for any 

 length of time, say two or three months, they will not 

 germinate the season following; and peaches and plums 

 have actually to be in the ground all winter to insure 

 their germination the succeeding spring. Seeds will ger- 

 minate much quicker when freshly gathered than after 

 they have dried, because heat, moisture, and air have 

 easier access to them, and act more quickly on them. 

 These facts, of which all are well aware, show the necessi- 

 ty for moisture, and the nature of its influence. 



