THE SLEEP OF PLANTS 



303 



RED CAMPION AT MID-DAY. 



the hours of darkness. Thus the Tobacco 

 flowers are visited by the long-tongued 

 hawk-moths, whilst the Campion attracts 



other night-flying species. It is remark- 

 able how clearly the white discs of 

 these flowers show up even on a dark. 



WHITE CAMPION AT MID-DAY. 



WHITE CAMPION AT 6 p m. 



