DR. J. MURIE ON THE MANATEE. 39 



form of .a great flat nervous band lying on the scalenus. Here it sends off a strong cord, 

 which is joined moreover by a branch from the median division of the seventh or sixth 

 nerve already alluded to — the cord in question constituting a large thoracic nerve with 

 ultimate divisions and twigs supplying the parts on the front of the chest, pectoral and 

 partially abdominal muscles. The main continuation of the eighth nerve pursues a 

 course down the fore limb as the ulnar ; but two much thinner branches with terminal 

 divisions derived immediately beyond its (8 trunk) expansion appear to represent the 

 internal cutaneous and nerve of Wrisberg. Moreover the thoracic branch of the eighth 

 nerve is joined by another from the seventh nerve, while at the origin of the ulnar 

 there is a communicating branch also derived from the seventh. 



On the Brain. — Both Dr. Chapman and Prof. Garrod in their papers (already quoted) 

 have taken exception to the description of the brain given in my former paper, and no 

 doubt justly correct me in attributing to it too many convolutions. In other particulars 

 also they do not concur with my reading of the parts. Each, moreover, has given his 

 own illustration, said to be from the fresh specimen shortly after the animal's death, 

 and therefore under advantageous conditions as compared with my own. Taking these 

 circumstances into consideration, it would be expected there should be a certain har- 

 mony between the figures particularly of these two observers, granting their better 

 opportunities for examination of the brain. But, on the contrary, their individual 

 representations are totally diverse. Which author, therefore, is the more reliable ■? or, 

 rather, to put it gracefully, wherein lies the incongruity, and in what respects does one 

 or other, or both, dissent from that heretofore given by myself? 



There are two aspects for consideration, text and illustration. Dealing with the 

 descriptive text, a careful analysis of statements as compared with my own, irrespec- 

 tive of paucity of convolutions already mentioned, elicits Dr. Chapman to assume : — 

 1, greater relative height of cerebellum ; 2, less differentiation of corpora albicantia ; 

 3, posterior shortening of corpus callosum ; and, 4, a different interpretation of what 

 constitutes the sixth, seventh, and eighth pair of nerves. Number 1 may be accounted 

 for by my specimen of brain having been preserved in spirit; number 2 I make no 

 special mention of; and to numbers 3 and 4 I shall again refer. In all other points, 

 allowing for variation of verbal expression, he substantiates my description of the parts '. 

 Prof. Garrod mentions that : — 1, there is no septum lucidum ; 2, the anterior com- 

 missure of the third ventricle is small ; 3, the pineal gland^ is small ; 4, as also are the 



' With regard to the Dugong's brain mentioned by me without reference, and inquired after by Dr. Chap- 

 man {I. c. p. 454), it was to the cast of the brain-cavity in the College-of-Surgeons Museum, and not to the 

 brain itself, that I meant allusion. 



■ I may here take note of an awkward error in lettering in my former memoir (p. 199, 5th line from bottom), 

 where pi is spoken of as pineal gland, parts of base, instead of pituitary body ; while in pi. xxv. figs. 33, 34, 

 pi is placed both on the pituitary body and also on the pineal gland, thus leading to confusion of these parts. 



