TSE FBUIT. 61 



for a long time and then finally germinate when favorable 

 conditions obtain. It is estimated that a large Elm produces 

 upward of half a million and a single Tobacco plant and 

 many other weeds ten to forty thousand seeds, numbers 

 which are small in comparison with those of the spores (cor- 

 responding functionally to seeds) produced by Puff-balls and 

 other Fungi. This great fecundity should be borne in mind 

 when considering the dispersion of plants. The spores of the 

 lower plants are extremely small, and they can be readily 

 transported by the slighest breeze. They are found literally 

 everywhere, as the universal occurrence of Moulds, Mildews, 

 Blights, etc. testifies. 



F 



