AMERICAN 
OFFICIAL PUBLICATION OF THE 
BOTANICAL SOCIETY OF AMERICA 
"S- \\\\ 
' JF Av 
/&S?.- - \ 
CONTENTS 
Symposium—The Species Concept: 
From the point of view of a geneticist... 
From the point of view of a morphologist...R. A. Harper 229 
From the point of view of a physiologist and bacteriologist__ .Guilford Reed 234 
From the point of view of a plant pathologist..E. C. Stakman 239 
The relation of the enzym pectinase to infection of sweet potatoes by Rhizopus 
L. L. Harter and J. L. Weimer 245 
The inheritance of flower types and fertility in the strawberry. W. D. Valleau 259 
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Entered as second-class matter February 21,1914, at the post office at Lancaster, Pa., under the act of March 3, 2879 
