PROPAGATION OF PLANTS. 187 



plant. These can generally be determined by their 

 external and internal appearance. If in cutting the 

 larger seeds the substance of the seed be of the natural 

 color, and the embryo be fresh and perfect, it will prob- 

 ably germinate. So if externally the}' have a clear color 

 and a fresh, plump appearance, they will be likely to 

 grow. The soundness of those that sink in water when 

 good (and most seeds do), may be tested by putting them 

 in warm water. Nearly all sound seeds will sink in this 

 fluid in a short time. Of the finer seeds, a skillful eye 

 will determine the quality with the microscope. But 

 the surest test is planting a few properly in a pot, pro- 

 tecting the surface from drying with a square of glass, 

 and keeping it in a warm room, or plunged in a hot-bed 

 or in a pit, giving it the heat naturally required by the 

 species for germination. A simple seed tester can be 

 made by the use of cheese cloth, on which the seed are 

 spread, covered with another cloth and placed on moist 

 sand, the whole covered with a board slightly raised to 

 permit of circulation of air. 



Seeds are more often unsound from mouldiness or age 

 than from not having been properly ripened. They should 

 be stored where they will be least affected by the pres- 

 ence of moisture and the changes of temperature. About 

 40°, but not lower, is said to be the best. Many oily seeds 

 become rancid, and will not vegetate when sown. 



Generally, seeds should be kept dry, but acorns and 

 chestnuts thus kept soon lose their vitality, and must be 

 kept until planted in rather dry loam, or slightly damp- 

 ened moss, well packed. Nearly all seeds keep better in 

 closely packed dry soil, the air being thus mostly ex- 

 cluded, than hermetically sealed in bottles. In close 

 stopped bottles or jugs, the air often becomes saturated 

 with the moisture and exhalations from the seeds, which, 

 in the impure, damp, close atmosphere, soon become com- 



