and like the rest of the sharks a water-breather, has a bulk of 

 body comparable to that of the larger whales. It has a large 

 brain cavity but a very small brain in a small part of this large 

 cavity. (It is very difficult to find the weight of these brains to 

 compare with that of the cetacea and other mammals.) The 

 problem of brain weight versus body weight versus intelligence 

 is most clearly expressed by Gerhardt von Bonin in his paper in 

 the Journal of General Psychology (1937).' He gives a very ex- 

 tensive table for mammals, their brain weight, their body 

 weight, and the values of 2 parameters for their specification. 

 He then states, "it is clear from all that has been said above that 

 the figures given here are nothing but a description of facts, a 

 description which, in the mathematical sense of the term, is the 

 'best' one. It does not pretend to make any enunciation about 

 the relation of intelligence and brain weight. For that purpose 

 we need a much broader psychological basis than we have at 

 present. 



"Former attempts to analyze the relations between body 

 weight and brain weight suffer from three deficits: (i) they 

 presuppose a correlation between intelligence and brain weight, 

 (2) they make suppositions about the intelligence of animals 

 which are unproven, and (3) they are based on a conception of 

 cortical function which can no longer be considered valid . . . 

 There is a close correlation between the logarithms of brain and 

 body weight, and this co-relation is linear. Brain weight in- 

 creases as the 0.655th power of body weight. The value of the 

 cephalization co-efficient k differs from species to species. 

 Whether or not this is an indicatio7i of the intelligence of 

 animals must he left to the psychologists to answer." 



One of the problems that the whales have, as compared to, 

 say, the large shark, is breathing air while living in the sea. This 

 requires that these animals reach the air-water interface rela- 

 tively frequently — at least every one hour and a half for the 

 bottlenose whale (Hyperoodon), three-quarters of an hour for 



37 



