54 



ADMONT H. CLARK 



be siud to be factors ill controlling node formation and develop- 

 ment both in the lymjih sac and along the peripheral lynij)hatics. 

 The relations of the peripheral lymphatics to the sac and the 

 development of nodes thus described are constant. 



The superficial cervical plexus needs a very careful description. 

 It is clear that it is an important structure since it drains so large 



rijj;. ;5 Injcctod jugular lymi)h sac, sui)orficial cervical lynii^h i)loxus and the 

 poriphoral lyniplialics in tlic neck of an (Miihryo pig moasurinfi ri.5 cm. long. Mag- 

 Tiiticd about 7.5 limes. This figure is to bo compared with figure 5 in The American 

 Journal of .Vnatomy, )>. ISS, vol. :5, 1<H)4, which is a complete injection of the super- 

 ficial lymi)hatics of the same stage. A.n, the apex of the jugular sac making the 

 lymi>h gland of the posterior triangle; A.c, anterior curvature of the lymph sac 

 making the deep jugular lymi)h gland; C.p, superficial cervical lymph plexus; 

 S.g, submaxillary lymph gland; S.s, stalk of the jugular lymph sac. 



