THE L YMPHA TICS AND L YMPHA TIC GLANDS. \ 09 



The follicles and medullary strands are never closely applied 

 to the sheath and septa (Figs. 104, 105 ) ; a system of clefts is 

 always left. We shall soon learn their signification. 



The follicle (Fig. 105) consists of reticular connective tissue 





Fig. 105. — Follicle from a lymphatic gland of the dog, in vertical section ; a, reticular frame- 

 work of the more external, ^, of the internal portion ; c, fine reticulum of the surface of the follicle ; 

 ei, origin of a larger, and e of a finer lymph tube ; f, capsule : g; septa ; k, division of the one ; i, in- 

 vestment space and its tenter-fibres ; k, vas afferens ; /, attachment of the lymph tubes to the septa. 



(Fig. 105, b and a), containing an excessive number of lym- 

 phoid cells. At the surface the meshes of the connective 

 tissue reticulum become much more narrow (c). 



From it arise fibres which, attached to the inner side of the 

 capsule and the outer surface of the septa, keep the follicle 

 stretched, as the frame does embroidery. I once named them 

 " tenter-fibres," and the cup-like spaces permeated by them, 

 the "investment spaces" of the follicle (?'). The follicles 

 themselves are held together in numbers, side by side, by 

 connecting bridges of their own tissue. 



The same tissue, containing lymphoid cells, and having 

 either its own vessel in its axis (Fig. 105, d, e, 106, a) or an 

 entire rectilinear capillary reticulum (Fig. 107, a), forms the 



