Vol. X 
FEBRUARY 
» 1923 
No. 2 
AMERICAN 
OFFICIAL PUBLICATION OF THE 
BOTANICAL SOCIETY OF AMERICA 
CONTENTS 
Alternation of sexes and intermittent production of fruit in the spider flower (Cleome 
spinosa).............A. B. Stout 57 
Internal decline of lemons I. Distribution and characteristics. 
E. T. Bartholomew, J. T. Barrett, and H. S. Fawcett 67 
The relation of temperature to the Fusarium wilt of the tomato. 
Edward E. Clayton 71 
Amylase in the spores of Rhizopus tritici and Rhizopus nigricans 
L. L. Harter and' J. L. Weimer 89 
Observations on the causes of gregarious flowering in plants...... William Seifriz 93 
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Entered as second-class matter February 21, 1914, at the post office at Lancaster, Pa. y under the act of March 3, 287 9 
