THE ANATOMY OF THE WEDDELL SEAL. 
847 
11. The relatively simple character of the mesencephalon. 
12. The small size of those parts of the cerebellar hemispheres which in man 
would constitute their main bulk; and the large size of those objects in relation to 
the vallecula, which in man would be relatively small. 
13. The reduction in the posterior margin of the pons Varolii, which thereby 
permits the bulbar root of the 5th cranial nerve to emerge directly from the side of 
the medulla oblongata. 
LITERATURE. 
- 
Moris, Trans. Zool. Soc. Lond., vol. viii., 1874. 
, Wispersunim and Parker, Comparative Anatomy of Vertebrates, 3rd ed., 1907, p. 224. 
Cunnincuam, Text-Bovk of Anatomy, edited by Cunningham, 3rd ed., -p. 512. 
Sir Wm. Turner, Challenger Reports, vol. xxvi., Zooloyy: Report on Seals (“Brain of Elephant Seal and 
of Walrus,” p. 89 ef seq.; plates viii., ix., x.). 
is provided. 
In connection with this Report a very full bibliography 
DESCRIPTION OF PLATE. 
Fig. 1. The left cerebral hemisphere, natural 
’ size. 
Ff. Sy. Fissure of Sylvius. 
Ff. Ro. Fissure of Rolando. 
S. P-c. Pre-central sulcus. 
S. Cr. Sulcus cruciatus. 
S. I-p. Intra-parietal sulcus. 
I, R. Island of Reil. 
Fig. 2. Mesial surface of the right cerebral hemi- 
a 
sphere. 
S. Cr. Sulcus cruciatus. 
F. Ro. Fissure of Rolando. 
I. P-o. Internal parieto-occipital fissure. 
Op. C. Optic commissure. 
C. C. Corpus callosum. 
Hy. C. Pituitary body. 
P. Var. Pons Varolii, 
Pin, Pineal body. 
TRANS. ROY. SOC. EDIN., VOL. XLVIII., PART IV. (NO. 30). 
Fig. 3, Basal surface of cerebral hemisphere. 
Rh, f. Rhinal fissure. 
Ff, Sy. Fissure of Sylvius. 
S. Col. Sulcus colateralis. 
C. f. Calearine fissure. 
P. o. Parieto-occipital fissure. 
S. D. Sulcus dentatus. 
O. T. Olfactory tract. 
Op. N. Optic nerve: 
Hy. C. Pituitary body. 
Cr. C. Crus cerebri. 
Is. Isthmus. 
Cun. Cuneus. 
G. L. Gyrus lingualis. 
Fig. 4. Vertical transverse section through the 
posterior horn of the lateral ventricle of 
the right hemisphere, viewed from behind. 
C. f. Calcarine fissure. 
V. Lateral ventricle. 
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