APPENDIX. 



555 



not continued into them, as in many quadrupeds ; 

 nor do they wind so much outwards as in the hu- 

 man subject, but pass close round the posterior 

 ends of the thaiami nervorum opticorum. The 

 thalami themselves are large, the corpora striata 

 small ; the crura of the fornix are continued along 

 the windings of the ventricles, much as in the hu- 

 man subject. The plexus choroides is attached to 

 a strong membrane, which covers the thalami ner- 

 vorum opticorum, and passes through the whole 

 course of the ventricle, much as in the human 

 subject. The substance of the brain is more vi- 

 sibly fibrous than I ever saw it in any other ani- 

 mal, the fibres passing from the ventricles as from 

 a centre to the circumference, wdiich fibrous tex- 

 ture is also continued through the cortical sub- 

 stance. The whole brain in the Piked Whale 

 "weighed four pounds ten ounces. 



The nerves going out from the brain, I believe, 

 are similar to those of the quadruped, except in 

 the want of the olfactory nerves in the genus of 

 the Porpoise. 



The medulla oblongata is much smaller in pro- 

 portion to the size of the body than in the human 

 species, but still bears some proportion to the 

 quantity of brain ; for in the Porpoise, where the 

 brain is largest, the medulla spinalis is largest ; 

 yet this did not hold good in the Spermaceti 

 Whale, the size of the medulla spinalis appearing 

 to be proportionally larger than the brain, which 

 was small when compared to the size of the ani- 

 mal. It has a cortical part in the centre, and 



