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DISCOVERY REPORTS 

 extended hunting. A similar explanation may lie behind the unexpected appearance of 

 numbers of Sei whales in whaling returns elsewhere, such as those summarized by 

 Kellog (1929). If, on the other hand, these unexpected appearances really occur, they 

 will probably be found to coincide with the occurrence of unusually high sea temperatures. 

 Figs. 109 and no give the length frequencies of both sexes of the Sei whale in the 

 whaling catches at South Georgia and South Africa for several seasons. The curves for 



lotai Length in metres 



Fig. 109. Sei whale. Males. Length frequencies. 



Fig. no. Sei whale. Females. Length frequencies. 



South Georgia show a great preponderance of adult whales of both sexes, but the curves 

 for South Africa are quite different. They are bimodal, especially for the females, and 

 show that the catches are composed of a very high proportion, more than 50 per cent, 

 of immature whales. Immature males and those which have just reached sexual 

 maturity preponderate and there is a second peak in the graph showing a group of 

 older and fully adult animals. The females fall into two well-marked groups, those 



