34 POULTRY DISEASES 



caudalis) supplying the mesentery and small intestine. 

 The posterior aorta also gives off ]uml)ar arteries and 

 renals, the latter supplying the kidneys, also arteries to the 

 testes (testicular) in the male and ovarian arteries supplying 

 the ovary in the female. At the hind extremities there is 

 given off the external iliac at a line near the junction of the 

 anterior and the middle thirds of the kidney. This supplies 

 the pelvic and outer muscles of that region. The aorta di- 

 vides into two branches, the ischiatica, and also sends an 

 artery back along the under side of the caudal vertebra (the 

 sacralis media). The ischial artery, in company Avith the 

 ischial nerve, passes through the foramen ischiaticum, giv- 

 ing off branches to the muscles of that region. 



The pulmonary veins, two in number, originate from a short 

 stem (pulmonary artery) which springs from the right ven- 

 tricle. These veins furnish the lungs with functional blood, 

 which is returned to the heart through pulmonary veins en- 

 tering the left auricle. 



There are three venous trunks carrying the venous ])lood 

 from the body and extremities. These are a left and a righc 

 anterior vena cava (vena cava cranialis) and a posterior vena 

 cava (vena cava caudalis). These three vessels empty into 

 the right auricle. Each anterior vena cava receives the jugu- 

 lar and subclavian vein of its respective side. The right 

 jugular is larger than the left. They are located ventrally 

 to the skull, where they anastamose through an oblique vein. 

 (It is at this point that a bird is stuck in slaughtering.) At tlie 

 inferior portion they receive blood from the vertebral vessels. 

 They receive branches from the head (the cranial vein), also 

 neck and back vein. The subclavian receives the blood from 

 the veins of the breast and wing (sterno-clavicularis and 

 thoracic-cranialis and caudalis, mammary and axillary veins). 

 The subclavian empties into the anterior vena cava. 



The posterior vena cava is short and receives the blood from 

 the external and internal iliacs, hepatic, renal hypogastric and 

 coccygeal veins. It also receives the ])lood irom the porta 

 hepatis, which collects blood from the abdominal viscera, es- 

 pecially the intestines. 



THE BLOOD OF NORMAL FOWL 



The blood of the fowl is made up of organized and unor- 

 ganized elements. The unorganized part is plasma and the 

 organized cells. Tlie cells are elliptical-shaped nucleated I'ed 

 blood cells measuring 7x12 microns, oval nucleated throm- 

 bocytes, and white blood cells. The white blood cells consist 

 of mast cells, eosinophiles, ])olymorphonuclear leukocytes, 

 large mononuclear leukocytes and lymphocytes. The red 



