LYMPHATIC SYSTEM OF THE OX AND SHEEP 727 



nerves. The one most often present is at the acute angle between the vena cava 

 and the diaphragm. The afferent vessels come from the diaphragm and medias- 

 tinum. The efferent vessels go to the posterior mediastinal glands. 



The bronchial lymph glands (Lgg. bronchiales) are situated on the termination 

 of the trachea and on the bronchi. Commonly three or four are present. One (Lg. 

 bifurcationis sinistra) constantly occurs on the left side in the angle between the aortic 

 arch and the left division of the pulmonary artery (Fig. 389) ; it is crossed laterally 

 by the vena hemiazygos. This gland is about an inch to an inch and a half (ca. 2.5- 

 3.5 cm.) in length and an inch (ca. 2.5 cm.) in width; it is often very irregular in 

 shape. A gland (Lg. bifurcationis dextra) is similarly situated on the right side in 

 the majority of cases. It is smaller than the left gland and appears to be absent 

 in about 25 per cent, of subjects; in some cases, on the other hand, two glands occur 

 here. In about half of the cases a small gland (Lg. bifurcationis dorsalis) is situated 

 above the bifurcation of the trachea. Another gland (Lg. eparterialis) occurs at the 

 origin of the bronchus of the apical lobe of the lung. Exceptionally a second small 

 gland is present here. The afferent vessels of these glands come chiefly from the 

 lungs and the pulmonary lymph glands, the thoracic part of the oesophagus, and the 

 heart.-' The efferent vessels of the left gland are quite variable. They may join the 

 common efferent of the posterior mediastinal glands. Those of the right gland go 

 to a middle mediastinal gland, those of the dorsal gland go to the right gland, and 

 those of the apical gland go to anterior mediastinal glands. 



The pulmonary lymph glands (Lgg. pulmonales) are inconstant and variable 

 nodes which may be found on the chief bronchi in the lungs. They appear to be 

 absent in one-third to one-half of the cases on one side or both. They vary in size 

 from a fifth to half an inch or more (ca. 0.5-1.5 cm.) in length. The afferent vessels 

 come from the lungs, and the efferent vessels go to the bronchial and posterior 

 mediastinal glands. 



It is worthy of note that in some cases lymph vessels of the left Imig go to glands on the right 

 (middle mediastinal glands), and lymph vessels of the right lung go to the left bronchial gland. 



The pericardiac lymph glands (Lgg. pericardiacse) are small and variable nodes 

 which lie on the pericardium. The left gland is usually present and is situated at 

 the space between the aortic arch and the vena hemiazygos. In some cases it may 

 be unusually large — nearly three inches (ca. 7 cm.) in length — and extend back to 

 the left bronchial gland. Other small glands may be found in this vichiity or lower 

 down. The right gland is only exceptionally present. It is situated just ventral 

 to the termination of the posterior vena cava. The afferent vessels come from the 

 pericardium, and the efferents go to the dorsal mediastinal glands (or their efferents) 

 or to the left bronchial gland on the left side, to the apical bronchial gland or an 

 anterior mediastinal gland on the right side. 



The sternal lymph glands (Lgg. sternales) are situated along the course of the 

 internal thoracic vessels. The largest, distinguished as the anterior sternal gland 

 (Lg. sternalis cranialis), is embedded in the fat in front of the transversus thoracis. 

 It is about half an inch to an inch (ca. 1.5-2.5 cm.) in length. The other glands are 

 covered by the transversus thoracis, and vary in size, number, and arrangement. 

 There is not one at every interchondral space, and, on the other hand, two may occur 

 at one space. The last of the series is often situated in the angle between the eighth 

 and ninth costal cartilages and the sternum and may escape notice.^ The afferent 

 vessels come from the diaphragm, the intercostal, deep pectoral, serratus ventralis, 

 rectus thoracis, and abdominal muscles; the costal and mediastinal pleura, the 



1 Baum notes the curious fact that in many cases in which he injected the lymph vessels of 

 the diaphragmatic lobes the vessels went around the dorsal gland without entermg it. 



2 Attention was recently drawn to this gland by Stroh, who designated it the xiphoid glands. 

 It is not always prwent. 



