10. The spleen, parallel to the gastric portion of the pancreas. It is deep red (darker than the pancreas and not so brown as the liver) and is held against the great curvature of the stomach by a part of the great omentum.
11. The kidneys, close against the dorsal body wall and in contact with the caudal part of the liver.
12. The bladder, in the median line at the caudal end of the cavity, held in place by the suspensory ligament, which passes to the midventral line, and by the lateral ligaments.
13. The mesenteric glands, large grayish-red glands one to four centimeters long, more numerous in the mesocolon.
14. In the female, lying against the ventral surface of the rectum, the uterus. It divides into two horns which diverge. Near the end of each horn the ovary.
15. The peritoneum. Study and understand the description of it ([p. 218]). Dissect some of it free from the body wall. (Trace the folds by aid of a diagram and model.)
B. In the thoracic cavity:
1. The lungs. Each is divided into lobes, three on the left, four on the right. The caudal right lobe pushes the mediastium toward the left and thus lies in a pocket dorsocaudad of the heart and dorsad of the vena cava inferior.
2. The pleuræ. Each pleura is a membrane like the peritoneum. It covers the diaphragm and the thoracic walls and is reflected onto the lungs. Hence it is divided into costal and pulmonary portions. Read the description ([p. 217]) and trace their connection. Each pleura forms a closed sac.
3. The mediastinal septum or median vertical portion formed by the apposition of the medial walls of the two pleural sacs. It divides the thorax into halves.