278 



DISCOVERY REPORTS 



The course of events during the 1929-30 season, the fatness figures for which are 

 plotted in Fig. 8, was evidently somewhat different. In the first month the condition 

 of the Fin whales taken was fairly good, but they showed a steady decline until 

 December, and after that a steady improvement till the end of the season. Heavily 

 infected whales were leaner than the average in November, but considerably fatter in 

 all the other months. Yet the proportion of immature whales increased markedly after 

 the new year, and reached its maximum in February as usual, and from the diatom 



OCT 



NOV 



DEC 



JAN 



FEB MAR&APR 



Fig. 8. Skin Diatom Fatness correlation, 1929-30. The average tlL % of all Fin whales with thick or ex- 

 tensive film is shown by the pecked line, while the continuous line represents that of the total Fin whales 

 for which full data are available, t = Blubber thickness; L = Length of whale. 



data it seems highly probable that a considerable proportion of the January arrivals 

 came from the north. One is forced to the conclusion that the movements during this 

 season were too complex to be followed in detail by the combination of indirect methods 

 available, but that three strong probabilities are still detectable: firstly, that at the 

 beginning of the season an unusually large proportion of the whales present had either 

 wintered south, or arrived on the grounds before the season began; secondly, that 

 there was a fairly constant replacement of these, mainly by mature whales that had not 

 been long within the Antarctic Zone, throughout the first half of the season; and 



