104 



TENTH LECTURE. 



simple and at the same time extremely effective method of 

 injection. We allude to his " puncturing method." 



The point of a fine canule is carefully forced into a tissue 

 which is thought to contain lymphatics, and an attempt is 

 made to carefully and slowly inject a wounded lymphatic. 

 Many of the attempts are, it is true, thoroughly unsuccessful, 

 still practice makes the master, and with patience and perse- 

 verance the object is finally accomplished. Teichmann's ele- 

 gant work on the lymphatics, not to mention others, has 

 shown this. 



Let us commence first with the chyliferous vessels which, 

 at the termination of an abundant digestion, by their fatty 

 contents stand out as dark canals. 



In the intestinal villus (Fig. 95), there lies, occupying the 

 axis, a caecal canal (d), surrounded by a looped reticulum of 

 capillaries (b, b\. Its transverse diameter is 0.0187 to 0.0282 

 mm. At the first cursory examination it is a lacuna; with 

 more accurate investigation one recognizes here, as elsewhere, 

 the thin walls formed of plates of cemented endothelial cells. 

 The condition just mentioned also characterizes the re- 

 maining portion of the lymphatics. The canals of the latter 



are more irregular, angular 

 and wider, and situated nearer 

 the interior. They are again 

 surrounded by the external, 

 much finer and more regular 

 capillary net-work of the 

 blood current. 



Let us now pass from the 

 intestinal villi, further down- 

 wards, and examine the infe- 

 rior flatter portion of the 

 mucous membrane of the 

 small intestine in which these 

 caecal lacteals from the intes- 

 tinal villi bury themselves. 

 Let us look at Fig. 99. Here, in connective tissue con- 



Fig. 99. — Transverse section through the mu- 

 cous membrane of the small intestine of the 

 rabbit (near the surface); a y the reticular con- 

 nective tissue containing lymph cells; b, lymph 

 canal ; c, transverse section of a Lieberkuhn's 

 gland ; the same with the cells ; e, f, g, blood- 

 vessels. 



