THE CENTRAL ACOUSTIC LOBE 



65 



indirectly through the i:)iieiimatic bulb, but becomes vestigial in 

 G^'ninarchus. 



The conformation of the brain in the Mormyrids has been, and 

 still remains, a wonder to the naturalist, and a puzzle to the biologist 

 and neurologist, so that the literature on the subject is large and 



ol/JuO- 



Coi/i. 



1<U\ <ffil\ 





/. 



in, V.C 



i'd.ujih^ v,C 



'/xJSt. U)ih(> VC . 



Fig. viii. — Brain of Mormyrus kannume after Burne. 

 V.C. — Valvula cerebelli. lob.impar. =lob. acustico-lateralis. 



diffuse ; according to the Cambridge Natural History, the brain is so 

 large as to attain a weight which equals one-fifty-second to one- 

 eighty second of the total \veight of the fish, and this great increase 

 of size is due almost entirely to the hypertrophy of what is known 

 as the " valvula cerebelli." 



