CATTLE. 



numerous and harge, and blood in large quantities pours on toward 

 the right auricle and ventricle of tiie heart. These tendinous cords, 

 and the muscular columns beneath, are very large and strong, in 

 order to aftbrd adequate resistance to the greater pressure of the 

 blood. In this ventricle, there is also a band or fleshy muscle, run- 

 ning across from one side to the other, the double effect of which is 

 beautifully evident, viz., to prevent this cavity from being too much 

 dilated, or possibly ruptured, Avhen the blood flows rapidly into the 

 heart ; and to assist the ventricle in contracting on the blood. A small- 

 er and more tendinous band runs across the same ventricle, lower 

 down, and for the same purpose. From the peculiar arrangement of 

 the circulatory system, there is always this pouring on of blood to be 

 arterialized ; for the secretion of milk, or the deposition of fat, con- 

 stitute the daily, unremitting duties of the animal. There is given, 

 not only to provide against accident, but to fit the heart for this 

 incessant hard work, this supplemental muscle, in the form of a lleshy 

 band stretching across from one side to the other, preventing dilata- 

 tion and assisting in contraction. 



The blood is diiven out of the riorht ventricle into the luno^s, and is 

 there exposed to the action of the atmospheric air, and purified ; 

 thence it is returned to the left auricle, passes into the left ventricle, 

 and, by the contraction of that cavity, is propelled through the arteries. 



The aortas are the large vessels which first receive the blood from 

 the heart in order to carry it through the body. The vessels from 

 the left ventricle, which carry the arterial blood through the frame, 

 and those from the right ventricle, that convey the venous blood to 

 the lungs, alike spring from the muscular and fleshy septum, or wall, 

 that separates the cavities of the heart, and divides that organ into 

 two distinct parts. The ventricles of the heart of the ox have con- 

 stant and hard work to do, and additional strength is given by the 

 insertion of a bone into the septum at the base of these arteries, more 

 belonging to the aorta than to the pulmonary artery, but meant as a 

 support to both. 



The heart is subject to inflammation. It is principally recognized 

 by the strength of the pulse, and by the bounding action of the heart, 

 evident enough when the hand is placed on the side of the chest, and 

 which may be seen and heard even at a distance. 



THE ARTERIAL SYSTEM. 



The blood is carried on through the arteries by the force of the 

 heart. These are composed or three coats ; the outer, or elastic, by 

 which they yield to the gush of blood ; the muscular coat, by wiiich 

 the artery contracts again when the gush of blood has passed ; and 

 the inner, or smooth, glistening coat, which lessens the friction of the 

 blood against the side of the vessel, and its consequent gradual retar- 

 dation in i's course. 



