GERMINATION CAPACITY 623 



10 days being the time usually allowed for most seeds, such 

 as Cereals, Clovers, Peas, and Turnips. 



14 days are needed for the Umbelliferse, e.g., Carrot and Parsnip, 

 and for Mangel, Rye-Grasses, and Timothy (Phleum). 



21 days for all the grasses except those mentioned above, 

 and the Meadow-Grasses {Pod) and Florin (Agrostis) for 

 which 28 days are needed. 



Instead of using damp blotting-paper as a seed-bed, various 

 other substances may be employed, such as folds of flannel, 

 damp sand and ordinary garden soil. Sawdust is not satis- 

 factory, as substances are often present in it which check 

 germination and destroy the radicle and other parts of the 

 embryo as soon as they make their appearance from the seed. 

 For small seeds blotting paper is sufficient, flannel being more 

 suitable for the larger ones. Sowing in pots of sand and earth 

 is generally unsatisfactory, as the seeds cannot be observed 

 during their development. Some seeds are, however, bes 

 germinated in sand, especially mangel with its rough, irregular 

 husk, as only in this way can an even supply of water to the seed 

 be maintained ; the sand penetrates into the crevices all round, 

 and water is carried to the seed regularly by capillary action. 



For grasses and similar small seeds, thin slabs of porous 

 earthenware, placed in shallow tins containing water, are often 

 used with more satisfactory results than when paper is employed. 

 Sufficient water penetrates through the porous slabs to supply all 

 that is required by the seeds. Sometimes porous flower-pot 

 saucers arranged in the same manner are utilised with excellent 

 results. These have the advantage of cheapness, and like the 

 slabs, are easily cleaned by washing in boiling water. Where 

 sand is used as the seed bed they are especially useful. 



Many and varied are the contrivances which have been de- 

 signed for purposes of testing the germination of seeds; the 

 above examples are, however, sufficient for ordinary work. It is 

 necessary that the supply of water, air, and suitable tempera- 



