134 NORMAL HISTOLOGY. 



cords whose function we do not yet understand. 

 The lymph-sinuses contain not only the fluid of the 

 lymph, but numerous lymph-cells, and usually a 

 certain number of red blood-cells. 



The principal blood-vessels enter the nodes at the 

 hilus, and the arteries, sending off branches to the 

 connective tissue there and to the septa, divide and 

 subdivide, and soon enter the lymph-cords ; they 

 pass along in the axis of these, giving off a long- 

 meshed capillary system ; then entering the nodules, 

 they break up into a loose capillary net-work, from 

 which the blood is collected into venous radicles, 

 and poured into veins which pass out through the 

 lymph-cords and out of the organ in connection with 

 the arteries. Small blood-vessels usually enter the 

 capsule at other points than the hilus, and are largely 

 distributed to the capsule and the connective tissue 

 of the septa. 



The number and arrangement of the nodules vary 

 greatly in different lymph-nodes : in some there is 

 but a single layer in the cortex ; in others, several 

 layers are superimposed and more or less crowded 

 thus giving to some nodes a narrow, to others a broad 

 and voluminous cortex. In many animals, as the ox, 

 the reticular tissue of the medullary portion contains 

 an abundance of brown pigment. 



There are, in many parts of the body, small dense 

 masses of tissue, some of them sharply circumscribed, 

 others diffuse and merging into adjacent tissues, 



