/,'. Sabin. 



that • better than the actual process of growth by Bprout- 



\\ which the veins are formed. 



spires of the models from embryos measuring ', mm., 

 for example fig. •'!•'>. represeni lymphatics in the early plexus stage; 



I Wo not, however, find any mention of the presence oi U I. Figure 



the beginning of the enlarging of the plexus into sa< -. From 

 their later si -. it; to 65, bul much better from Lewis, fig. 6 



. cm In' made "in the especial characteristics of the jugular 

 i . are i l ) thai tin- jugular Bac in the cal arises 

 from the posterior cardinal vein as well as from the anterior cardinal 

 rein. This point i< well shown in Euntington and McClure figures. 

 i •.' ) The cerebral end of tin- rentral or jugular portion of the Bac is 

 rery large. This is th< part that drains the larynx. (3) The internal 

 ar trunk is small. (I) The dorsal apes of the. sac which lies 

 in the posterior triangle of the neck is large. (See Lewis' fig. 6.) It 

 is connected with the cerebral end by a slender vessel. In injections 

 of the sac in embryos between 30 and 60 mm. long ii Looks very much 

 sac in ;i bovine embryo as shown by Polinsld ( 101 ) in his fig. 

 "t. It lies nearer the arm than the corresponding portion of toe sac 

 in the i>i'_ r . (5) There is a large extension though possibly a dis- 

 tinct sac (Lewis, fig. 6) along the primitive ulnar and thoracoepi- 

 gastric veins. This sac is very conspicuous in older stages, extending 

 into the axilla and receiving large trunks from the thoracic wall, 

 makes the jugular lymphatic sac in the cat more like the human 

 than the |iiu r I sec. V |. 



seg ntal divisions of the sac a- indicated by colors in the 



Euntington and McClure figures air arbitrary and nut as valuable 

 as the divisions 1 have jusl ljimh. which correspond to the function 

 ■ if '!n' differenl glands which develop from tin' sac. 



Lewi-' figure also Bhows a verj interesting view of the retroperito- 

 neal ami ilia. as a continuous plexus, whirl: again emphasizes 

 the fact that the n-nal sacs anastomose with each other. 



'.. 1'i:im\i;v Lymphatic System in Birds, Posterior Lymph 



Beart lnd .Ii i;ii.\i; \a \i rn S u . 



The history of our knowledge of the lymphatic system in birds is 

 mosl interesting. Tin- early discoveries >>\' the posterior Lymph hearts 

 by Panizza, A. F. .1. Mayer, ami Stannius, a- well as the work of 



