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BRIEFER ARTICLES. 



NUTATION IN BIDENS AND OTHER GENERA. 



(with four figures) 



There has long been a belief, regarded by many as a mere super- 

 stition, that the sunflower turns with the sun. In 1898' and in 1900^ 

 Schaffner published a series of illustrations and observations demon- 

 strating conclusively that such a nutation exists. He makes no men- 

 tion of any plant other than species of Helianthus that exhibit this 



Fig. I.— A single plant of Bidens frondasa, taken at 10 a. m., showing the east- 

 ward morning nutation. 



'Observations on the nutation Helianthus annuus. Box. Gaz. 25: 395-403- 1^9^ 



1903] 



The nutation of Helianthus. Box. Gaz. 29: 197-200. 1900. 



363 



