KNOWLEDGE OF WHALE MOVEMENTS AT SOUTH GEORGIA 



263 



month groups. It was found that such other sources of distortion as were Hable to creep 

 in through the use of so large a time unit were for the most part easily detected when 

 working up the detailed records. 



SUMMARIZED OBSERVATIONS 



A brief summary of the monthly observations at South Georgia, and of the scantier 

 data obtained at the South Shetlands and at the ice edge to the south of Africa, is given 

 in this section. In order to test how far the South Georgia catches departed from 

 the average conditions described in the last section, a very large amount of numerical 

 data has been examined, which has only an indirect bearing on the problem in hand 

 and has therefore been omitted from this paper. The main points revealed by these 

 additional data may be stated first, the detailed monthly figures given later all relate to 

 the actual occurrence of diatoms upon the whales. 



Table I 



Showing the actual numbers of whales taken at Grytviken, South Georgia, 



during the months in which skin-film observations were made 



From Table I it will be seen that during the seasons studied Fin whales were much 

 more consistent in their occurrence on the South Georgia grounds than Blue whales, 

 and were particularly abundant in 1929-30. Examination of the maturity data for that 

 season, on the criteria laid down by Wheeler (1930), showed that it was a typical 

 "fin-whale year" (cf. Harmer, 1931, pp. 142 et seq.). Adult whales predominated early, 

 and a large ncrease in the proportion of immature whales, that reached a marked 



