28 



FATE OF PRIMARY LYMPH-SACS IN ABDOMINAL REGION OF PIG, ETC. 



With the growth of the embryo these sacs come to lie entirely lateral to the aorta in 

 approximation to and above the retroperitoneal sac, which likewise has become 

 situated lateral to the aorta. 



These three sacs are connected by small channels which show in figures 2 and 4, 

 and when they are transformed into lymph-glands the result is a rather confusing 



V I 3iaph 



D thor. 



V.l.ql. suprar. 



61 suprar.' 



V.l.coli des. 



Rect. 



V. I. sacr. lot 



Ao.abd 



Nod iliomqA 



FIG. 4. Dorsal view of specimen seen in figure 1, showing primary lymphatics dorsal and dorso- 

 lateral to the aorta, namely, the thoracic duct, cisterna chyli, and the paired iliac sacs. 

 Lymphatics injected with india-ink through the thoracic duct. Drawing from specimen 

 by J. F. Didusch. 



mass of right and left juxta-aortic lymph-nodes which is made up of glands aris- 

 ing from lymphatics both dorsal and ventral to the aorta, and which extends from 

 just above the hilum of the kidney to the bifurcation of the aorta, forming the 

 main mass of lumbar nodes of the adult. Since the glands arise not only from 

 the ventral and dorsal sacs, but probably also along some of the anastomosing 

 vessels between these sacs, the resulting lymph-glands in the adult are exceedingly 



