414 



ELEANOR LINTON CLARK 



still follow a definite path through the axilla into the deep plexus, 

 and a small anterior portion of the supra-scapular lymphatics. 



Injections of such embryos show definite large and compara- 

 tively straight channels over the side and pelvis. A channel 



Fig. 4 Chick of 6 days, 22 hours (19.5 mm.). Stage of stronger lymph heart 

 pulsations and posterior circulation in most of the superficial lymphatics. Flow 

 is still anterior in axillary region and in anterior portion of the supra-scapular 

 region. Injection shows newly formed channel connecting supra-scapular lym- 

 phatics with those of the side, and large channels over the side and pelvis. L.H ., 

 lymph heart. X 5. 



posterior to the shoulder, draining a small ventral portion of 

 the side and running through the axilla is still present, while 

 a narrow duct, connecting the lymphatics dorsal to the shoulder 

 with the main side channel, has developed; this stage is illustrated 

 in figure 4. 



