The Nature and Consequences of Social Behavior and Social Organization — Continued Page 
3. Sexual Behavior and Reproduction 152 
A. Sexual Behavior 152 
B. Seasonal and Maturational Aspects of Reproduction 158 
4. Utilization of Space 160 
A. Home Range 160 
B. Dispersal With Reference to Age 170 
C. Intercolony Affiliations 171 
D. The Function of Group Structure in Altering the Frequency of Contact Between Rats. . . 172 
E. Contacts Between Groups 175 
5. Sociality 176 
A. Social Rank and Social Stress 176 
B. Criteria for Judging Social Rank 176 
a. Proximity to Goals 176 
b. Size and Age 177 
c. Social Genealogy 177 
d. Place of Residence and Associates 177 
e. Competition During Early Life and Rate of Growth 177 
f. Observed Outcome of Combat 177 
g. Sex Ratio of the Colony 177 
h. Reproductive Success 177 
C. Culture 178 
D. The Role of Aggressive Behavior in Social Organization 179 
a. Nose-touching 179 
b. Avoidance Behavior 179 
c. The Combat 180 
d. The Chase 181 
e. The Relationship of Estrous Females to the Frequency of Fighting and Chases 183 
f. Territoriality — Expulsion of Strangers from Burrows or Harborage Boxes 184 
g. Defensive T erritoriality — Hole Plugging 186 
h. Offensive Territoriality 186 
E. Conditions Influencing the Frequency and Outcome of Aggression 188 
a. Sex 188 
b. Age and Size 189 
c. Season 191 
d. Availability of Food 191 
e. Social Rank and the Acquisition of Food 194 
F. The Syndrome of the Social Outcast 195 
G. Locality of Birth and Social Status 196 
H. History of Male Dominance 198 
a. Summary of Male Dominance and Its Implications 202 
I. Development of Local Colonies 203 
a. General Remarks About the Colonies as They Existed in the Spring of 1949 204 
J. Stress and Reproduction 214 
6. Growth, Health and Mortaility 216 
A. Growth of the Individual 216 
a. Average Growth Curves 217 
b. The Maturity Index 220 
c. Chronological Order of Birth 221 
d. Changes in Rate of Growth 223 
e. Further Remarks on the Chronological Order of Birth 223 
f. The Time Between Litters as This Influences Competition and Growth 232 
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