A QUANTITATIVE STUDY OF VARIATION IN 
THE BRACTS, RAYS, AND DISK FLORETS OF 
ASTER SHORTII HOOK., A. NOVZE-ANGLLE L, 
A. PUNICEUS L, AND A. PRENANTHOIDES 
MUHL., FROM YELLOW SPRINGS, OHIO. 
GEORGE HARRISON SHULL. 






CONTENTS. PAGE 
I. Introduction III 
IL Matora ios wc 112 
III. Methods and Precautions 114 
IV. Results 115 
Aster shortii Hook. I15 
Aster nove-anglie L. 118 
Aster puniceus L. IIQ 


Aster prenanthoides Muhl 
Result of Successive Collections 







(1) Bracts 
(2) Rays tie ta 
(3) Disk Florets eee a i 
(4) Correlations 145 
V. Discussion of Results 146 
VI. Summary 15! 
Bibliography 552 

I, INTRODUCTION. 
THE work upon which this paper is based was done in the 
Biological Laboratory of Antioch College, during the academic 
year 1900—1901, under the direction of Prof. W. L. Tower. 
My primary object was to study the variations of several 
species of Aster by means of the statistical methods, to deter- 
mine whether the results of Ludwig (95, '96, '98) upon Chrysan- 
themum leucanthemum L. were also true for other nearly allied 
forms, and to find out, if possible, how much correlation there 
1 Contributions from the Biological Laboratory of Antioch College, No. 5. 
III 
