THE SEI WHALE 



231 



edged with white internally, was not examined until it was largely dismembered, a 

 matter for regret, as it was reported by the whaling foreman to be a " Bryde's whale". 

 The remains examined, however, were all indistinguishable from the typical Sei whale 

 except for this streak in the baleen. PI. XIX, fig. 2, shows a plate of this baleen, which 

 except for the coloration is typical Sei whale baleen. 



Where white plates occur together with the white spot on the side of the snout they 

 coincide in position with it, but white plates commonly occur without the white spot, 

 and, on the other hand, one case is recorded in which the white spot was present but 

 all the plates were pigmented. In all whales in which white plates were present on one 

 side only it was the right side on which they occurred: the numbers are not sufficient 

 to draw definite conclusions, but this may be an indication of a tendency to asymmetry 

 as is found in the Fin whale. The number of white plates present varies from nil to 

 the greatest recorded number of forty-five on one side, though CoUett (1886) records 

 up to fifty-eight in the Sei whale of the northern hemisphere. This may be compared 

 with the condition found in the Fin whale where the average number of white plates 

 on the right side is 152, maximum 200 and minimum 68. 



The width of the longest baleen plates at their base has been recorded in twenty-four 

 Sei whales, all from South Georgia: these measurements are given in Table XV. From 

 these figures it is seen that the width of the baleen of this species is very much less, 

 varying from 28 to 50 per cent of its length, than in the Blue and Fin whales, where 

 the corresponding figures are 67-106 per cent and 60-73 per cent respectively. The 

 figures show an increase in breadth, together with increase in the percentage value, as 

 the whales increase in total length from 12 to 16 m., showing that the baleen increases 



Table XV. Sei whale. Baleen width 



