54 PROPAGATION 



strong light. In the absence of any of these conditions successful 

 germination cannot take place. When the seed-coat or shell is 

 hard and horny, it precludes air and moisture from the embryo, and 

 thus prevents germination until it has sufficiently decayed. Certain 

 seeds with extremely hard shells or endosperm take a long time to 

 germinate, varying from 2 or 3 months, as in the case of the 

 Nutmeg, to almost as many years, as with certain species of palms. 

 In many cases, however, germination may be assisted by either 

 tiling or rasping the horny shell, or subjecting them to repeated 

 soakings in almost boiling water. The former method may be 

 applied to seeds with a hard horny shell, as those of Ceara-rubber 

 (Ma iii hoi Glaziovii), while the latter may be adopted in the case of 

 seeds with a very hard endosperm, as Indian-shot (Canna), Wattles 

 (Acacia), and other leguminous sorts. The "rasping" or "tiling" 

 process is perhaps best carried out by holding the seed, when 

 large enough to handle, for a few seconds against a revolving grind- 

 stone. A cooly with a seed in each hand, while another cooly 

 turns the handle, will thus soon get through a large number of seeds. 

 A method, known as the "bush method," sometimes adopted for 

 hard-shelled seeds, is to burn a small bundle of hay or ferns over 

 the seed-pot or bed, afterwards watering the soil with a tine rose. 

 Another way of facilitating the germination of very hard seeds, is 

 to place them in a hot fermenting dung heap. Indian Shot (Canna)* 

 Ceara Rubber seeds and others have been successfully started in 

 this way. Soaking such seeds for about 5 minutes in a solution of 

 sulphuric acid has been tried with good results in America. In 

 hastening the germination of old or hard seeds, camphor dissolved 

 in water has been found to have a marked effect. Experiments 

 have also shown that treating seeds with chlorine water (2 drops 

 chlorine to 60 CC. of water), and then placing them in the sun 

 will accelerate germination. Another aid to germination is to water 

 the seeds with a weak solution of formic acid (1 in 500), or with 

 alkaline substances, as ammonia, soda, etc. 



Testing vitality of seeds. A popular \vay of testing the 

 vitality of seeds is to place them in water, when if they float they 

 are presumed to be bad. This, however, is sometimes misleading, 

 as some seeds when in their prime tioat, and sink when in a bad 

 condition, or vice versa. Seeds will either sink or float according 

 to their specific gravity. Those which sink when good are of 

 doubtful character when they swim. A strong saline solution, 

 made with common salt, is employed in Japan for testing rice and 

 other seeds. In this case, as above, all seeds that float are rejected, 



