RESPIRATION IN SOUTHERN WHALES 397 



from the air and consuming oxygen, so that the manometer was further deflected by a 

 negative pressure on the dummy side of the apparatus. While a more or less constant 

 manometer reading was obtained after 10 min. shaking, it was found that if the system 

 was allowed to stand for some hours a further deflection of the manometer was recorded, 

 indicating that some form of metabolism was proceeding at a slow rate. 



Oxygen capacities were again estimated in 1932-3 with the Van Slyke burette. 

 A Haldane haemoglobinometer was used in conjunction with the gas analyses, but the 

 results are subject to an error of 10 per cent, since, as afterwards appeared, the haemo- 

 globinometer was faulty. Variable capacities and haemoglobin percentages were again 

 found, but the actual and theoretical capacities agreed to within 3 vol. per cent. The 

 average oxygen capacity of seventeen samples was 14-1 vol. per cent. The haemoglobin 

 in the same samples averaged 9-00 per cent, which is equivalent to an oxygen capacity 

 of 1 2- 1 vol. per cent. 



The haemoglobin percentages from South Georgia and the oxygen capacities found 

 in 1932-3 indicate that the blood of Blue and Fin whales has small haemoglobin content 

 and hence small oxygen capacity. It might perhaps be thought that it would be to the 

 whale's advantage to have blood with a large oxygen capacity for purposes of storage. 

 This would be so if the whale stayed long enough at the surface for all the blood to come 

 into contact with fresh air. But, since a whale seldom takes more than two or three 

 breaths in quick succession, its need for haemoglobin is regulated by the volume of 

 oxygen which can be contained in the lungs^ for transport throughout the body during 

 submersion. 



The oxygen capacity of porpoise blood was estimated by Morimoto, Takata, and 

 Sudzuki (1921). Two samples gave capacities of 42 and 45 vol. per cent. The red 

 corpuscles amounted to 8-4 and 11-2 million per c.mm. respectively, and it was inferred 

 by the writers that the high oxygen capacity was due to the increased number of cor- 

 puscles rather than to a high percentage of haemoglobin in each corpuscle. The haemo- 

 globin percentage is not recorded, nor is the method by which the oxygen capacity was 

 estimated. It may be that such a high oxygen capacity was obtained by the use of a 

 Barcroft manometer, while the blood may have had some features in common with the 

 blood of Blue and Fin whales. 



Oxygen dissociation curve. It was not found possible to work out a dissociation 

 curve of whale blood because the blood when fresh from the dead whale is always acid 

 in reaction. It was necessary always to make the blood alkaline before a successful 

 estimate could be made of oxygen capacity. In the circumstances it would not have been 

 profitable to attempt a dissociation curve since it would have been necessary to derange 

 the blood reaction and salt content to some extent before starting. 



1 For this reason the function of oxygen storage, suggested by Ommanney (1932) for the fat of the retia 

 mirabiha, seems improbable. 



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