From Embryology

Huntington GR. The development of the mammalian jugular lymph sac, of the tributary jjrimitive ulnar lymphatic and of the thoracic ducts from the viewpoint of recent investigations of vertebrate lymphatic ontogeny, together with a consideration of the genetic relations of lymphatic and haemal vascular channels in the embryos of Anmiotes. Amer. J Anat. 16: