THE LYMPHATIC SYSTEM. 



97 



ymphatics of the largo intestine. 



ject of the arrangement seems to be to submit the liquid contained in 

 the lymph vessel to the action of the pulpy material of the gland and ar- 

 terial blood under the most favorable circumstances, the thinness of the 

 wall and the convolved plexus being well adapted to that end. 



Fig. 34 illustrates the lymphat- 

 ics of the large intestine, the ad- 

 joining parts being cut or displaced 

 to display them ; <2, <z, ascending 

 and transverse colon drawn aside; 

 &, , descending colon and its sig- 

 moid flexure drawn aside ; <?, cce- 

 cum; d, stomach; e, duodenum; 

 y, jejunum cut ; <?, A, i, lymphatics 

 and their glands. In such an ar- 

 rangement as this, the lymph is far 

 more perfectly exposed to the in- 

 fluences to which it has to be sub- 

 mitted than it could possibly be in 

 straight tubes. In reptiles, how- 

 ever, this package is not resorted 

 to, and the tubes, being spread out, 

 give the false appearance of a great- 

 eT'cfevelopment to this system than in the higher tribes. In the mam- 

 malia, according to Professor Goodsir, wherever the lymph tube enters 

 the gland, it changes its internal constitution, losing the scale-like cover- 

 ing that its inner coat presented, and offering a numerbus development 

 of nucleated cells, many of which adhere to the membrane beneath, but 

 many float away and drift with the lymph in its course. There is a 

 constant reproduction of these organisms, and they seem to be connected 

 with a diange in the albumenoid constituent of the lymph, Production of 

 turning it into fibrin. And thus, if examination is made of fibrin in lymph 

 the lymph before it enters a gland and after it has passed s lands - 

 through, in the former instance it seems to differ but little from the liquor 

 sanguinis, or serous portion of the blood, as has been already shown, but 

 in the latter fibrin begins to abound. 



Professor Goodsir's view is represented in the diagram, Fig. 35, show- 

 ing the scale-like ep- 

 ithelial cells of the 

 lymphatic tube chang- 

 ing into the nucleated 

 cells of the gland. 



Diagram of a lymph gland. Evolution of cells in lymph gland. Fig. 36 illustrates 



the generation of broods of cells, some being attached and some free. 



G 



Fig. 85. 



Fig. 36. 



