; •.' . j ■'■■in. 



VIII. \ Al.'lul - OTHER THEORIES l\ REGARD TO THE 

 ORIGIN AM» DEVELOPMENT OF THE LYMPHATIC 

 S"S STEM. 



1. M LYER-LEWIS Am m,i \. 

 In the precedii a given a consistent accounl of how 



the lymphatii off from the vein- and gradually in 



The places where the lymphatics bud off vary in different 



j; ia the amphibia and reptiles, and in the case of the post 



lymph hearts in birds the primary lymph sacs lie in the myotomes and 



striated muscle and become lymph hearts. In the higher forms 



interior lymphatics come from the anterior cardinal vein and it* 



branches, the caudal lymphatics '1" not develop (mammals) and the 



Fin. 18. — Diagram to show the theory of Ranvier and myself that the 

 lymphatics arise Crom the veins. The veins are striped, the lympl 

 dotted. 



rior lymphal e from tie ?ena cava and renal vein-. From 



of origu Li ed all the lymphatics i body 



down to the ultimate capillaries. 



! without opposition. 1 1 

 I it was mad< irst theory of the origin of the lymphatics 



that they anise in the periphery as dilated tissue spaces and 

 towards the cent* i and (39). This was questioned by Sala 

 (137), showing that the first lymphatics in birds were against the 



-. and by my proving in L902 that the jugular lyi - are 



the first lymphatics in mammals and that they bud m the 



anterior cardinal veins. Thus I substituted for the tl ries shown in 



