The Behavior of Seeds Toward Water. 23 



we shall find that the first lot will swell the fastest, the 

 second next and the third slowest. Few seeds will ab- 

 sorb enough water from damp air at ordinary tempera- 

 tures to swell much. 



b The points of contact. If we^weigh, two lots of 

 100 beans each, on a delicate balance, and mix each lot 

 with well-crumbled, moist loam in a fruit-jar, packing 

 the loarn tightly in one of the jars, and leaving it as 

 loose as possible in the other, close both jars to prevent 

 evaporation, and after twenty-four hours sift the beans 

 out of the loam and weigh the two lots again we shall 

 find that the beans in the jar containing the compacted 

 loam have increased more in weight than the others. 

 This indicates that the beans in this jar have absorbed 

 water faster than those in the other, because they were 

 in contact with the moist loam at more points. 



c Temperature. If we fill two bottles with beans, 

 adding~ice water to one, placing it in a refrigerator, and 

 lukewarm water to the other, setting it in a warm room, 

 we shall find that the beans in the latter bottle will swell 

 more rapidly than those in the former. This shows that 

 a warm temperature favors the absorption of water a 

 fact that is true of all seeds. The same would have 

 been true had we planted the beans in two samples of 

 moist earth, placing these in different temperatures. 

 (^ dThe nature of the seed-case* In the bean, Indian 



* The term seed-case is here used to designate the outer cov- 

 ering of the seed as the word seed is understood by the seedsman 

 or planter. Every seed, as we buy it in the market, or when 

 ready for planting, has one or more covering layers. In the pea- 

 nut, for example, what we here call the seed-case is commonly 

 called the shuck; in the cocoanut it is called the shell; in the 

 bean and Indian corn it is more often called the skin. In botany, 

 the outer coverings of seeds are given different names, as peri- 

 carp, testa, etc., according to their exact office in the make-up of 



