42 DR. J. MURIE ON THE MANATEE. 
the sixth, their origin can be traced towards the medulla oblongata outside the latter. 
As regards the compound eighth nerve, funiculi respectively constituting glosso-pha- 
rangeal, pneumogastric, and spinal accessory are clearly distinguishable. The ninth 
nerve (hypoglossal) is equally manifest, and derives its filaments from a more median 
line than the divisions of the eighth. In short, the cranial nerves, as a whole, are 
derived from nearly their normal situation, as obtains in the Mammalia generally. 
Lastly, in connexion with the brain, I have in Plate IX. given the vascular distribu- 
tion. The circle of Willis is complete; but the internal carotid and basilar artery 
seem relatively small, while the other cerebral branches take on somewhat a retial 
character. 
Concluding Remarks.—Vhe present communication of necessity has led to a few items 
of controversy ; but while supporting my own former observations and views, I have no 
wish to detract from the really useful papers of my fellow anatomists. 
The most important points are those in connexion with the brain and the cranial 
and cervical nerves. As to the brain, I with pleasure acquiesce in the emendation of 
its comparatively smooth surface’; but I am dubious as to Garrod’s figures giving its 
natural contour and details correctly, sine gua non. I moreover think the minor dif- 
ferences of special parts mean nothing more than variety in expression rather than 
established facts; for with separate specimens to work on, and under dissimilar condi- 
tions and aspects, each individual has consequently seen from his own point of view. 
As to the cranial nerves, I could have much wished Dr. Chapman had supplemented his 
remarks by a good figure of the brain’s base; for in his attributing my lettered eighth 
nervous funiculi (J. ¢. pl. xxv. figs. 32, 33) to a pars intermedia considerable ambiguity 
arises ; besides, against his idea there is the weighty fact that the said filaments spring 
as usual from the side of the medulla oblongata. 
* The accompanying woodcut (fig. 2) is reduced from a rough sketch made now fully ten years ago, pre- 
vious to extraction of the brain of the female Manatee dis- 
sected by me. By accident it and a few notes had got mislaid 
and lost sight of when preparing my material for the press. 
Had it been otherwise they might have saved me falling into 
errors of interpretation of supposed conyolutions, magnified by 
spirit-preparation and surface-scaling. I do not offer this as 
an apology; for one must be judged by their publication, be 
it right or wrong. To me, however, Prof. Rolleston’s words 
have some meaning :—“ Persons, however, to whom an inner 
conviction of their own accuracy may be dear in the face of 
adverse criticism, may learn from this the advisability of pre- 
serving such documentary evidence as that to which I have 
referred.” (Rolleston versus Lankester, “ Blood-corpuscles of 
the Annelides,” Cambr. Journ. of Anat. and Physiol. vol. xii. 
p. 404, April 1878.) 
