METABOLISM 3O9 



it is known that in Canada and Sweden the annual increase in the 

 number of registered diabetics is 14 per cent. 



In these circumstances, it is becoming increasingly difficult to meet the 

 ever-growing demand for insulin from normal sources of supply. Of the 

 forty-four member states of the World Health Organization twenty-four 

 reported a shortage of insulin in 1948, amongst them not only Norway and 

 Japan, which lack a pastoral economy, but also France and Switzerland. 

 The great cattle countries of South America, Australia and South Africa 

 can, no doubt, step up their insulin production much further, but the 

 time will probably come when whales will have to be used as well. A Fin 

 Whale has a pancreas weighing an average of seventy-seven pounds, i.e. 

 as much as the glands of about 100 cattle, while the pancreas of a Blue 

 Whale is equivalent in weight to those of 200 cattle. On the other hand, 

 the insulin yield per pound of Cetacean pancreas is only about 50 per cent 

 that of cattle, and the organ must be removed immediately after death 

 and kept refrigerated. For all these reasons, it is still not an economic 

 proposition to embark on the large-scale production of whale insulin. 

 However, the situation may well change, and, if it does, Jorpes (1950) has 

 calculated that the annual Antarctic catch will yield i ,500 tons of pancreas, 

 a quantity sufficient to cover the present insulin needs of a country with 

 a population of about twenty-five million (e.g. Poland, Turkey, or the 

 combined Benelux countries). 



No discussion of an animal's metabolism is complete without some 

 mention of the liver, which plays so important a part in it. The liver of 

 Cetaceans is divided into two lobes by a shallow indentation in its lower 

 edge, and it occasionally has an intermediate lobe as well. It is dark red 

 in colour, and in Rorquals it may weigh as much as a ton. It is devoid of a 

 gall bladder (see Chapter 10). 



Since the liver plays such an important part in an animal's metabolism, 

 we fully expect its weight to decrease with increase of body mass since, as 

 we have seen, the bigger a given animal the smaller its metabolic rate. 

 However, when we compare the ratio of liver to total body weight of 

 porpoises (average = 3-2 per cent) and dolphins (average = 2-2 per cent) 

 with the corresponding figures for rabbits (4-3 per cent), small dogs 

 (3-3 per cent), large dogs (2-4 per cent), man (2-7 per cent) and horses 

 (i -I per cent), we may safely say that Odontocetes have an inordinately 

 large liver for their mass. The same is also true of Rorquals and Sperm 

 Whales, which, according to Quiring, have percentages of 0-9 and 1-5 

 respectively, while the figure for the very much smaller elephant, which 

 might have been expected to have a higher percentage, is only o -8. Seals 

 (3 '9 P^i" cent) have a liver-to-body weight ratio which, size for size, is 



