PREFACE 
The twenty-third annual report of the Missouri Botanical 
Garden comprises the report of the officers of the Board, the 
twenty-third annual report of the former Director and 
seven scientific papers, the result, for the most part, of work 
done in the Graduate Laboratory at the Garden. 
The twenty-second report was issued on February 14, 
1912, which marks the date of publication of the scientific 
papers contained. 
The reports are sent to scientific institutions and a 
limited number of individuals, in exchange for publications 
or desirable material for the various Garden collections. 
They may be purchased at approximately the cost of publi- 
cation from the Missouri Botanical Garden, Messrs. R. Fried- 
lander & Sohn, Berlin, or William Wesley & Son, London. 
GeEorGE T. Moore. 
Sr. Louis, Mo., December 1, 1912. 
(4) 
