18 EXPERIMENTS WITH PLANTS 



substances of this sort (salts, starch, sugar, etc.), and 

 we suppose that the seed owes to them its power to 

 absorb water. Now we have just found, in the experi- 

 ment with sugar in the boats, that water is absorbed 

 more rapidly than syrup. Is it so in the case of the 

 seed ? Place weighed lots of seed of the same kind in 

 water, in syrup and in a very strong solution of com- 

 mon salt (dissolve as much salt as you can in the 

 water). After a day or so remove the seeds, dry 

 them on the surface and weigh. Can you make the 

 solution strong enough to prevent all absorption ? 

 Rinse the seeds in water and plant them in moist 

 sawdust, to see whether the sugar or salt have injured 

 them in any way. 



Do you think that the seeds will germinate in sea- 

 water? If this cannot be obtained it can be made 

 artificially by dissolving about 3% per cent of sea- 

 salt (obtainable at grocers' and druggists') or common 

 salt in water (4% drams of salt to a pint or 3% grams 

 to 100 cc. of water). The seeds may be placed in the 

 apparatus shown in Fig. 25, but cotton soaked in the 

 sea-water is to be substituted for the wire netting. 

 Are the seeds of plants which inhabit the seashore 

 able to germinate in sea-water? How is it with alkali 

 soils in this respect ? 



In the boat experiments just described, we are 

 struck with the fact that water appears to come 

 through the cover only where the sugar or germ is in 



