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ELEANOR LINTON CLARK 



In chicks of 8^ to 9 days, granules injected into the side lym- 

 phatics moved anteriorly, following the new dorsal path into 

 the supra-scapular lymphatics (where their movement became 

 retarded) and finally disappeared in the depth. Over the pelvis, 

 injected granules moved slowly posteriorly to a point near the 

 lymph heart where they stopped and appeared to oscillate for 



s.s.- 



Fig. 7 Chick of 8 days, 20 hours (25 mm.). Stage of anterior circularion 

 for side region and part of the pelvis; posterior circulation for the rest of the 

 pelvis; retarded flow in the supra-scapular region and over the posterior surface 

 of the pelvis; injection shows new lateral lymph channel has replaced the original 

 ventral one. L.H^., lymph heart; S.5., supra-scapular sac; P.S., pelvic sac. X 5. 



a few seconds. If the lymph heart contracted while they were 

 in this region the granules moved rapidly posteriorly into the 

 lymph heart, during the interval immediately after each beat. 

 If no pulsation of the lymph heart occurred, the granules, after 

 a few seconds of hesitation, flowed around a wide bend into an- 

 other pelvic channel and from there circulated anteriorly into 

 the side channels. In the embryo represented in figure 7, the 



