380 



FOUNDATIONS OB" BOTANY 



450. Study of Transportation by Water — Nothing less 

 than a long series of observations by the pond-margin and 

 the brookside will suffice to show how general and impor- 



FiG. 269. — Tumbleweeds ^ lodged against a Wire Pence in Winter. 



tant is the work done by water in canying the seeds of 

 aquatics. An experiment will, however, throw some light 

 on the subject. 



EXPERIMENT XL 



Adaptation for Transportation by Water. — Collect fruits of as 

 many aquatic, semi-aquatic, or riverside and brookside species of 

 plants as possible, place them on shallow pans of water and notice 

 ■what proportion of aU the kinds studied will float. Leave them 

 twenty-four hours or more and see whether all the kinds that floated 

 at first are still afloat. Some desirable fruits for this experiment 



1 Amarantus albus. 



