406 RANDOLPH WEST 



specific and spreads by a steady centrifugal extension * * * * 

 The buds send out processes forming clusters. From the clusters, in 

 turn, processes are sent out which anastomose with one another, form- 

 ing a plexus. Simultaneously^ processes grow toward the surface from 

 the clusters, and give rise to the superficial plexus of peripheral lym- 

 phatics of the posterior part of the body. There is no essential dif- 

 ference between the manner of growth of the peripheral lymphatics 

 and that of the plexus which is to form the lymph heart (p. 258). 



In June 1913 Miller ((3) in a preliminary note on the develop- 

 ment of the thoracic duct of the chick states that certain aggre- 

 gations of mesenchymal cells mentioned by Sala (1) "com- 

 prise developing blood cells which are differentiated in situ 

 out of the indifferent mesenchymal syncytium, that these blood 

 cells then gain access to the lymph channels making up the devel- 

 oping thoracic duct, and that finally the haemal cellular ele- 

 ments in question, reach the blood stream via the thoracic duct 

 and the jugular lymph sac." He clearly recognizes that lym- 

 phatic channels may serve to transmit blood cells arising in situ 

 in the mesenchyme to the haemal channels and distinguishes 

 this function of the lymphatics by the term 'haemorphic' He 

 further states that "the lymphatics arise as isolated lacunae 

 directly from mesenchymal intercellular spaces and are not in 

 any sense derived from the veins, and subsequently coalesce 

 to form the continuous channel of the thoracic duct." The 

 possibility of venous origin of these lymphatics or of the back- 

 ing up of their blood content from the veins is excluded by the 

 total absence of the azygos system in the Sauropsida. In his 

 completed paper of September 1913 Miller (6) gives his results 

 in greater detail. He states that the lacunae in question are 

 bounded at first by indifferent mesenchymal cells which become 

 flattened to form cells which are morphologically equivalent to 

 endothelial cells. 



Hoyer in June 1913 presented Fedorowicz's "Untersuchung 

 iiber die Entwickelung der Lymphgefiisse bei Anurenlarven" 

 (7) before the Academy of Sciences of Cracow. Fedorowicz, 

 working on Bufo vulgaris, Bufo viridis, Rana esculenta, and Rana 

 temjioraria found cell strands developing from the surface of 

 the lymph heart. In these strands intercellular spaces and 



