WOOL. ViETl MARCH, 1922 NO. 2 
rican MIDLAND 
AMERICAN 
Devoted to Natural History, Primarily 
that of the Prairie States 
Published by the University of Notre Dame, 
Notre Dame, Indiana 
J. A. NIEUWLAND, C.S.C., Ph. D., Sc. D., Edigér. 
CONTENTS | 
Seasonal Dimorphism in Arisaemae Triphyllum 
Theo. Holm 41 
The Evolution of Tools and Implements 
William D. Johnston 49 
Nomenclatorial Notes on Certain American Plants—II. 
Homer D. House 61 
The Geography of Bird Study 
O. A. Stevens 65 
Book Reviews Carroll Lane Fenton 69 
PRICE $1.50 A YEAR SINGLE NUMBERS 30 CENTS 
FOREIGN, 6s. 6d. 
Entered as second-class matter at Notre Dame, Indiana. Acceptance for mailing at special 
rate of postage provided for in section 1103, Act of October 3, 1917, 
authorized on July 3, 1918. 
THE UNIVERSITY PRESS, NOTRE DAME, INDIANA 
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