THE OLDER STAGES 139 



The sample examined consisted of 129 individuals measured to the nearest millimetre. For several 

 days after this the stomachs of the blue and fin whales brought to the factory all contained a high 

 proportion of Sixth Furcilias and early adolescent krill and in two notable instances whales were 

 recorded as having been feeding almost exclusively on this very young brood. The smallest euphausian 

 measured at this time was a Sixth Furcilia only 11 mm. long. Among his 'Vikingen' measurements 

 Ruud also records some very small individuals, the smallest 12 mm. long and almost certainly a SLxth 

 Furcilia. 



Table 24. Stomach krill measured at South Georgia during the season ig2g-jo with 



the percentage figures shown in brackets 



That these instances of such small whale food are not merely isolated ones without any real 

 significance is confirmed by the observations of other biologists who at various times during the last 

 20 years have worked in factory ships for the former Discovery Committee. Measurements of stomach 

 krill by Mr A. H. Laurie,^ for instance, on board the 'Southern Princess' in 1932-3 (Table 25) and 

 others by the late Mr Paul R. Crimp^ in the 'Hektoria' in 1939-40 (Table 26) lend strong support 

 to the view that late larval and early adolescent krill, in other words krill approaching the end of their 

 first year of growth, may contribute substantially to the diet of whales especially during the early part 

 of their sojourn on the southern grounds. Peters (1955) also reports a marked consumption of young, 

 approximately i-year old, krill during the early part of the season, especially in November and 

 December, but Nemoto (1959) states that his stomach samples did 'not show such tendencies'. 

 Nemoto's samples, however, came largely from the East Wind drift and since these high latitudes are 

 not open to shipping until January it is hardly surprising that he did not find the same abundance of 

 very small whale food then as is encountered (p. 370, Fig. 118 and p. 377, Fig. 123) in the more 

 northerly plankton in spring. He states that throughout the season his samples consisted of i-year and 

 2-year swarms in about equal numbers and this our summer East Wind measurements seem to show 

 (p. 397, Fig. 136) is what would be expected. He finds in fact that it is towards the end rather 

 than at the beginning of the pelagic season that his East Wind whales were feeding most heavily on 

 small (14-15 month old) krill, and there seems to be a simple enough explanation for this. With the 



1 To the nearest half-centimetre. ^ To the nearest miUimetre. 



14-2 



