io8 



TENTH LECTURE. 



induction lymphatic vessels, vasa afferentia, penetrate, for the 

 most part manifoldly, into its convex surface (f,f). The 

 educting vessel at the hilus (A) remains, at the same time, 

 frequently single. 



Fig. 104. — Section through one of the smaller lymphatic glands, with the current of the 

 lymph — half diagramatic figure ; a, the capsule; 6, septa between the follicles of the cortex 

 (d) ; c, system of septa of the medullary substance as far as the hilus of the organ ; e, lymph 

 tubes of the medulla ; f, lymphatic passages, which surround the follicles and flow through 

 the spaces of the medulla ; g, union of the latter into an afferent vessel (/i) at the hilus. 



It is surrounded by a connective -tissue sheath (Fig. 104, *, 

 T05, f) with a muscular admixture. This capsule continues 

 inwards in a similarly constituted but perforated septum (Fig. 

 104, b, c, 105, g, k), which finally unites towards the hilus in a 

 thicker connective tissue mass (" hilus-stroma " of His). In 

 the lymphatic glands of large animals this " septum system " 

 is immensely developed ; in small creatures it is often uncom- 

 monly slight. 



We distinguish in the lymphatic glands a cortical and a 

 medullary layer. The former consists of rounded or irregular 

 bodies of 0.5 to 2 mm. and more, the follicles (d), which in the 

 smaller organs are placed in single, and in larger glands in 

 double or manifold rows. 



The medullary substance is composed of reticularly united 

 strands, which spring from the inner side of the follicle, pass 

 through the septum, and thus constitute a connection be- 

 tween these structures of the cortical layer (Fig. 104,^,105, 

 d, e). The transverse diameter of the strands varies extraor- 

 dinarily, from 0.04 too. 13 mm. and more. 



