,506 ANATOMY OF VERTEBRATES. 



glands, ultimately join the mesenteric lacteals, and the contents 01 

 the whole intestinal system of absorbents are carried by a few 

 trunks to a ' chyle-receptacle,' fig. 399, n, at the root of the mesen- 

 tery, whence are continued the beginnings of the ' thoracic duct.' 

 § 342. Lymphatics. — These differ from the lacteals only in the 

 nature of their contents, and even this is a temporary or contingent 

 difference, for the lacteals convey a clear lymph, when the func- 

 tion of chylification is suspended. The gastric absorbents accom- 

 panying the right gastro-epiploic vessels communicate behind 

 the beginning of the duodenum with s lacteals ' and absorbents 

 from the liver : the gastric absorbents from the lesser curvature 

 join those of the liver descending ( Glisson's capsule : ' the ab- 

 sorbents accompanying the left gastro-epiploic vessels unite with 

 those from the spleen. The pancreatic absorbents communicate 

 partly with the splenic ones, partly with the duodenal lacteals. 

 The deep-seated absorbents of the liver, continued from the initial 

 plexuses already adverted to in the portal fissures, fig. 373, 

 emerge with the hepatic ducts, and are joined by those of the 

 gall-bladder and by many of the superficial absorbents : they 

 traverse glands in ' Glisson's capsule.' Some of the superficial 

 absorbents ascend along the coronary and lateral ' ligaments ' and 

 enter the thorax, independently of the trunks of the deeper-seated 

 ones. They combine with the absorbents of the heart and lungs 

 and those accompanying the ( internal mammary ' vessels to 

 form three or four trunks communicating with the thoracic duct. 

 The direct work of taking up waste tissues is done by indepen- 

 393 dent organites : the earliest recognition 



of absorbents is as intercellular spaces 

 or areolas (vol. i. p. 455), or serous cavi- 

 ties; the canals continued from which, 

 when filled by injected fluid, resemble 

 a ' plexus,' such as Breschet has deli- 

 neated in figure 393 : such plexiform 

 beginnings are commonly superficial, 

 as beneath the skin and the serous sur- 

 face of organs : in the substance of or- 

 gans and tissues the origins are ' lacunar' : 



Initial plexus of Lymphatics, clxviii". r , ,, n ,, n ° n , 



in both forms the free surface shows 

 nucleate scale-cells. When a distinct wall can be defined, the 

 lymphatics of Mammals are seen to be more numerous, mi- 

 nute, and ' highly finished ' than in lower Vertebrates. And, 

 though remarkable for their almost transparent delicacy, their 

 walls are strong, and in them may be distinguished fibrous layers 



