CONTENTS. 



Page. 



Abstract ^ 



I. Introduction ^ 



II. Material and Methods H 



III. Survey of the Strains; their Founders 13 



IV. Line A 1^ 



V. Line B 25 



VI. Line C 29 



VII. Line D 



35 



VIII. Line E 51 



IX. LineF. 



52 



X. Line G 62 



XI. Continuation of Line E '1 



XII. General Summary of Lines 77 



XIII. Heritability of Socially Effective Traits 78 



1. Calculating Ability 78 



2. Aggressiveness °2 



3. Perseverance °* 



XIV. Statistics 86 



1. The Population Considered °^ 



2. Comparative Efficiency of the Several Lines 86 



3. Comparative Fecundity 88 



4. Comparative Survival 89 



5. Differential Migration 89 



XV. Relative Effect of Environment and the Blood 91 



XVI. Marriage Selection 94 



XVII. Immigration 97 



XVIII. Conclusion 100 



Reference ^02 



3 



J^/V 



