14 



I'LANT PROPAGATION 



all parts of the world. The rules herein presented (29), 

 especially those concerning moisture and heat, are fol- 

 lowed with great care. Seeds such as acorns are very 

 difficult to transport long distances. Usually thick- 

 coated and bony seeds require moist, confined air; thin- 

 shelled ones, dry conditions. For shipping to or through 

 the tropics seeds are usually sealed in tin cases or oiled 

 packages. Most seeds, however, sent through ordinary 

 cool climates, after being thoroughly air dried, need be 

 placed only in cotton sacks, large paper packages or 

 manila envelopes. Apple, pear and other small seeds are 

 often mixed with powdered charcoal. 



Often more satisfactory results may be secured by 

 growing the seedlings of species very difficult to ship in 

 the seed form and shipping these either actively growing 

 in wardian cases or dormant as nursery stock. The 

 former method is not much practiced; the latter is the 

 favorite method of nurserymen. 



27. The rest period of seeds is that interval between 

 the' apparent maturity of the seeds upon the parent plant 

 and the time when the seeds will germinate under con- 

 ditions normal to the species. Such seeds apparently 

 cannot be made to sprout earlier. A 

 majority of garden seeds will sprout 

 within a month of the time they mature ; 

 a few almost without any delay. It is no 

 uncommon thing for seeds of cereals to 

 sprout while still in the head, should 

 the weather be wet for a consi;lera!,'; 

 time at harvest. The mangrove normal- 

 ly sprouts its seeds while still attached 

 to the parent plant. The rest period is 

 really a time of chemical change or 

 , pot in soil, b, dibble, ripening of the foods stored in the seeds. 

 It may be broken by drying, freezing, chemicals, or l)y 

 freezing and thawing. 



FIG. 11— 

 POT PLUNGING 



