nomena, because this enormous extent of the cerebral cortex to 

 receive and 'store' impressions of such vast sensory surfaces be- 

 comes a condition of survival of the animal. 



"The marvelous complexity of the surface of the cerebrum is 

 the direct result of its great size. In order, apparently, that the 

 cerebral cortex may be efficiently nourished and at the same time 

 be spared to as great a degree as possible the risk of vascular dis- 

 turbances [such as would be produced by large vessels passing 

 into it], its thickness does not appreciably increase in large 

 animals. [He then quotes Dubois' figures showing that the 

 whale's cortex is the same thickness as that of the human.] Such 

 being the case, it naturally results that the increased bulk of cor- 

 tex in large animals can only be packed by becoming thrown 

 into increasing number of folds, separated by corresponding 

 large number of sulci."* 



In regard to communication between individual whales, 

 Scammon in 1874 wrote the following: "It is said that the Cacha- 

 lots [Sperm Whales] are endowed with the faculty of communi- 

 cating with each other in times of danger, when miles . . . distant. 

 If this be true, the mode of communication rests instinctively 

 within their own contracted brains.'" Let us not forget that 

 Scammon was talking about the mammal with the largest 

 known brain on this planet. Instinct as the sole cause of com- 

 munication with a brain this size seems rather improbable. This 

 brain is not any longer considered "contracted." Both of these 

 statements illustrate an authoritative view of that time. If one 

 peruses the paper by Tokuzo Kojima, "On the Brain of the 

 Sperm Whale" (in the Scientific Reports of the Whales Re- 

 search Institute, Tokyo, VI, 1951, 49-72), one can obtain a 

 modern clear view of this brain. The largest one that he ob- 

 tained (from a 49-foot sperm whale) was 9,200 grams. The 

 average weight of the sixteen brains presented in his paper is 

 7,800 grams for average body lengths of 50 feet. (The brain 

 weight per foot of body length varied from 118 to 187 grams 



35 



