186 



The Development of the Lymphatics in the Skin 



reached the skin at a point over the crest of the ilinni. From this point 

 the ducts radiate to the skin over the side, back and liip. From no 

 other center of radiation for the primary lymphatics do the ducts spread 

 out so symmetrically, so like the spokes of a wheel, as in this case. In 



Fig. 3. A partial injection of the Ij^mphatic system in the sliin of a pi^ 

 long. The primary group of ducts is completely injected. X 3. 



3.5 cm. 



the neck there are several centers of radiation, so that no one center 

 sends out ducts in every direction. 



Fig. 5, from a pig 5.5 cm. long, is the last of the series. The injec- 

 tion was made by two insertions of the hypodermic needle, one over the 

 scapula with the needle opening toward the neck, and the other just below 

 the point of radiation over the crest of the ilium. In this way one takes 

 advantage both of the radiating direction of the ducts and of the larger 



