CHAPTER XIV 

 THE EEL. ANGUILLA VULGARIS 



In this chapter we propose to consider the feeding habits of the 

 common eel and its brain pattern, without any reference to the 

 other species M'hich spend their entire hfe in the sea, such as the 

 conger and the Moray or Muraena ; although we shall make some 

 reference to the olfactory lobe and organ of the conger. There is a 

 good description of the brain of the common eel by Burne in the 

 Catalogue of the Museum of the Royal College of Surgeons, from 

 which we quote. Looking at the brain from the dorsal aspect we 

 notice that " in front of the medulla the several regions of the brain 

 are approximately of the same size, and as each is more or less 

 clearly bilobed, the brain appears to consist of four pairs of rounded 

 equal-sized nodules, situated one behind the other. The anterior 

 pair (olfactory bulbs) are slightly pointed in front, and give off twa 

 large olfactory nerves. The optic lobes and cerebellum are divided 

 down the middle by a shallow groove. The cerebellum is consider- 

 ably broader than long. The medulla is small and much shortened." 

 But if the cerebellum is removed, it will be seen that acoustic 

 tubercles are not prominent and that they pass obliquely into two 

 elongated and narrow lobes which are the somatic-sensory lobes ; 

 these are continued caudally into the narrow vagal lobes. There 

 is no sign externally of any facial lobes. 



We must now refer to the same writer's description of the brain 

 of the conger, "it is remarkable for the large size of its olfactory 

 centres. It shows a decided right-handed rotation of its anterior 

 lobe. The olfactory bulbs are of great size. The right bulb lies 

 partly below the left, much as in the sole. The thalamencephalon 

 is remarkably long for a teleostean, forming a narrow neck between 

 the cerebrum and the moderately developed optic lobes," a descrip- 

 tion which applies almost equally well to the condition found in the 

 sole. 



We must make a chversion for a moment to point out that not 

 only are the olfactory bulbs of great size, but the olfactory organs 

 themselves are highly specialised. These have been described by 

 Bateson as foUows, " the olfactory plates lying within the organ are 



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