THE NERVOUS SYSTEM OF THE OX 837 
more than a third of the length of the hemisphere. The pattern of the fissures 
and gyri of the pallium is somewhat simpler than in the horse. 
1. The lateral fissure (of Sylvius) is very deep. Its middle branch extends almost ver- 
tically upward on the middle of the lateral surface of the hemisphere, and is separated by a gyrus 
of variable width from the suprasylvian fissure. The anterior branch runs forward about parallel 
with the sulcus rhinalis anterior, from which it is separated by the short gyri of the insula. The 
latter are covered to a small extent only by the overhanging gyri (operculum). The posterior 
branch may run back a distance of only about 1.5 em. and end in T-shaped manner, or it may 
join the sulcus rhinalis posterior. 
2. The suprasylvian fissure is deep and very distinct. It extends in an undulating manner 
from the lateral surface of the occipital pole to the lateral side of the sagittal pole. Here it may 
Cere- 
bellum £ 
Olfactory 
Olfactory 
Infundibulum tract 
bulb 
Hypophysis or pituitary body 
xa Corpus 
Medulla_trape- 
oblongata zoideum 
Fic. 664.—Brarn or Ox; Ricut View. 
Fissures: 1, Lateral; 2, 2, suprasylvian; 3, coronal; 4, transverse; 5, ectomarginal; 6, diagonal; 7, posterior ecto- 
sylvian; 8, presylvian; 9, 9’, rhinal (anterior and posterior); P.ch., chorioid plexus of fourth ventricle; P.c., cerebral 
peduncle; L.p., piriform lobe; J, insula. Stumps of cranial nerves are designated by Roman numerals. 
be interrupted or may be continued by the coronal fissure, which descends to the frontal pole 
and divides into two short branches. 
3. The diagonal fissure (S. diagonalis) begins in front of the stem of the lateral fissure and 
runs upward and forward. Its form is very variable. 
4. The transverse fissure cuts obliquely into the dorsal border in front of the sagittal pole. 
It is short and deep and commonly communicates with the suprasylvian and coronal fissures, but 
may be separated from the former. 
5. The marginal fissure is distinct. It extends from the sagittal pole to the occipital pole. 
It is flexuous and deviates outward somewhat in its posterior two-thirds. 
6. The entomarginal fissure lies medial and parallel to the posterior part of the preceding. 
7. The ectomarginal fissure is lateral and parallel to the marginal fissure. It does not ex- 
tend so far in either direction as the latter, and is often more or less broken up by annectant gyri. 
~ 8. The sulcus rhinalis is more open than in the horse, since it is not overlapped by the gyri 
above it. 
9. The calloso-marginal fissure is flexuous and not so regular as in the horse. It is often 
interrupted at or near the level of the genu of the corpus callosum, in which case the genual fissure 
continues it downward. 
10. The cruciate fissure is faint and is confined to the medial surface. It lies about one centi- 
meter in front of the transverse fissure, and commonly joins the calloso-marginal fissure below. 
