RESPIRATION IN SOUTHERN WHALES 



367 



greater in proportion to body weight ; conversely the basal metabolism of a whale may 

 be expected to be small. There is no convenient method of measuring the surface of 

 a whale, though various formulae have been suggested for calculating the area. For the 

 present purpose it will be sufficient to take the Blue whale as representing two cones 

 joined together by their bases, as Guldberg (1907) suggested. The base of each cone 

 may be taken to be a transverse section of the body at the occipital condyles. 



A female Blue whale was measured and weighed by Capt. Th. S0rlle at Stromness, 

 South Georgia, in 1926: the length was 27-18 m. (see Appendix, p. 404). The approxi- 

 mate area of the whole whale, calculated as above, was 275 sq. m. ; the basal metabolism 

 therefore would be 275,000 calories per day. The weight of this whale was approximately 

 122,000 kg. The calories per kg. per day necessary to support hfe would be 2-25. For 

 comparison the following figures are shown (Starling) : 



It would seem therefore that the Blue whale, of which this specimen is fairly typical, 

 has a very small basal metaboHsm in comparison with smaller mammals. A man of 

 70 kg. at rest absorbs about 300 cc. oxygen per minute on behalf of his basal metabolism, 

 that is to say 4-28 cc. oxygen per kg. of body weight per minute. The Blue whale's basal 

 metabolism is 14-6 times less than man's, so that the whale's oxygen requirements will 

 be only 0-293 cc per minute per kg. This whale, then, required 35-75 1. per minute of 

 oxygen, which is contained in 178-75 1. of air. 



Vital capacity. Direct measurement of a Blue whale's vital capacity, or the greatest 

 amount of air which can be taken in after the most forcible expiration, is impracticable. 

 The weight of the lungs of the whale under consideration was 1226 kg., 1-24 per cent 

 of the weight of the soft parts, whereas human lungs average 2-37 per cent. Another 

 Blue whale measured and weighed at the same whahng station in 1924 was 20-3 m. 

 long and weighed 48,903 kg. (see Appendix, p. 403). The lungs weighed 1-53 per cent 

 of the soft parts. 



If for the moment it is assumed that the lung's capacity is proportional to its weight 

 in whales and human beings, two facts emerge: (i) the whale's vital capacity is ap- 

 proximately half that of man in proportion to its weight ; (2) if the human vital capacity 

 is 3-50 1. for a man weighing 70 kg. (Starling), then the vital capacity of the whale first 

 mentioned would be 3050 1. (3-05 cm.). The minimum air requirements of the whale 

 were estimated above to be 178-75 1. of air per minute. At this rate the whale can stay 

 submerged for 17 min., assuming that all the oxygen in the lungs is used and that no 

 muscular exertion is taking place. The calculation, for lack of first-hand data, has been 

 based on the assumption that the capacity of the lung is a function of its weight. No 



