THE SCOURING-GRASS AND ITS SQUIRMING SPORES 



. 



twisting and wriggling the spores 

 leap from the glass, and the wind 

 then takes care of them. 



The secret of it all is very sim- 

 ple, however. These strange antics 

 being merely the singu- 





109 





lar hygrometric result of 

 evaporation from the four 

 filaments, for a drop of 

 water or even a careful breath 

 will cause them all to coil up as 

 when packed in the cone. This 

 curious exhibition may be seen 

 by almost any one, as the various 

 species of Equiseta are quite com- 

 mon in swampy districts every- 

 where, and a simple pocket micro- 

 scope, or even a strong magnifying- 

 glass is sufficient to show the 

 phenomenon distinctly, in itself a 

 sufficient quest for a walk at the 

 edge of the brook or swamp. 





