CONTENTS 



Introduction page i^ 



Material '^S 



Sex ratio 1^5 



External characters '°° 



Body proportions ^°° 



Colour 213 



Hair 227 



Ventral grooves 220 



Baleen 228 



Northern and southern Sei whales compared 232 



Food 234 



Blubber 234 



Parasites 238 



External 238 



Internal 239 



Reproduction 240 



The male 240 



External genitalia 240 



Testes 240 



Sexual cycle 240 



The female 242 



External genitalia 242 



Ovaries 243 



Uterus 246 



Mammary glands 246 



Gestation, breeding season and sexual cycle 248 



Growth and age 257 



Migration 268 



Economic status 275 



Summary 277 



References 279 



Appendix. Measurements 281 



Plates XVIII, XIX following page 2()q 



