THE 



AMERICAN NATURALIST 



Vol. XLIX. November, 1915 No. 587 



VARIABILITY AND AMPHIMIXIS 



PROFESSOR L. B. WALTON 

 Kenyon College 



A Comparative Study of the Variability in Zygo- 

 spores of Spirogyra in fiat a (Vauch.) formed by Lateral 

 (Close breeding) and by Scalariform (Cross breeding) 

 Conjugation, and its Bearing on the Theory of Amphi- 

 mixis and Correlated Problems 



L Preliminary outline 650 



1. Introduction 



2. Historical 



3. Material 



4. Methods 



