244 WHALES 



sensitive in Cetaceans. Moreover, when we consider that the heads of 

 Cetaceans are generally large, constituting as they do one-quarter to one- 

 thiid of the total length of the body of Mysticetes,then it is understandable 

 that their trigeminal nerve is so inordinately large. 



The facial nerve, too, is very thick in comparison with the seventh 

 cranial nerve of terrestrial mammals - no doubt because of the presence 

 of very well-developed blowhole muscles (see Chapter 4). The glosso- 

 pharyngeal (ninth cranial) nerve, which mainly supplies the taste buds of 

 the tongue, is very small, especially in Mysticetes, and the same applies 

 to the twelfth cranial nerve, the hypoglossal, which supplies the muscles of 



Figure 126. Top view oj the brain oj a Fin Whale. {Ries and Langworthy, igsy. 



