THE NERVOUS SYSTEM OF THE OX 



715 



of the preceding. They accompany the utero-ovarian arteries to the ovary and the 

 cornua of the uterus. 



The hypogastric or pelvic plexus (P. iiy])()gastricus) is the pelvic continuation 

 of the aortic antl jwsterior nu^senteric plexuses. The chief nerv(^s which form it 

 enter the p(4vic cavity ventral to the large vessels, anastomose with each other and 

 with branches from the third and fourth sacral nerves, and ramify on the pelvic 

 viscera. The peripheral plexuses derived therefrom are named according to the 

 organs which they supply; the chief of these are the haemorrhoidal, vesical, utero- 

 vaginal, prostatic, cavernous (of the penis or clitoris). 



THE NERVOUS SYSTEM OF THE OX^ 



The spinal cord resembles that of the horse in conformation and structure. 

 In cattle of medium size its length is about 165 to 170 cm. (ca. 65 to 67 inches) and 

 its weight about 240 to 250 grams _^ 



(ca. 8 ounces). __/" f -—^ 



In a cow 140 cm. in height Dexler 

 found the weight of the cord (inchiding 

 the intradural nerve-roots) to be 260 g. 

 and the length 162 cm. The lengths of 

 the regions were: cervical 41 cm., tho- 

 racic 72 cm., lumliar 32 cm., sacral 7 cm. 



The brain has an average 

 weight of about 500 grams (ca. 

 16 to 17 ounces). Its differences 

 in general form are correlated with 

 those noted in the consideration of 

 the cranial cavity. 



The medulla is short, wide, 

 and thick. Its ventral face is 

 strongly convex. The pyramids 

 are narrow, short, and close to- 

 gether in front. Near the decus- 

 sation there is a well-defined oval 

 prominence on either side which 

 indicates the position of the pos- 

 terior olive. The corpus trape- 

 zoideum is large; it has no cen- 

 tral part between the pyramids. 

 The external arcuate fibers are 

 distinct. The restiform bodies are 

 short and thick and tliverge more 

 strongly than in the horse. The 

 floor of the fourth ventricle is only 

 about two-thirds as long as in the 

 horse. The area acustica is a well- 

 marked oval prominence lateral to 

 the middle ])art of the limiting sul- 

 cus. Th(^ tuberculum acusticum 

 at the origin of the auditory nerve 

 The posterior recess of the fourth v 

 Magendie (Apertura mediana) with 

 ^ Only the most salient differences 



Fir.. 528. — Brain of Cow, Dors.^l View. 

 /, Sulcus transversus; 2, longitiuliiial fis.sure; 3, antero- 

 intern.al frontal gyrus; 4, olfactory bulb; 6, inarKinal or sagittal 

 pole of hemisphere; 6, lateral fis.sure (of Sylvius); 7, hemisphere 

 of cerebellum; 8, vermis of same; 9, accessory nerve; JO, dorsal 

 root of first cervical nerve. (EUenberger-Bauni, Anat. d. Haus- 

 tiere.) 



is very large. The anterior fovea is distinct, 

 entricle communicates through the foramen of 

 the subarachnoid space, 

 as compared with the horse will be mentioned. 



