XX.] 



LYMPHATIC GLANDS. 



237 



Lymph-path; M.C. Medullary cord. Silver 

 nitrate and hamiatoxylin, x 300. 



alcohol, stain in logwood and eosin, and mount in balsam. The 

 reticulum in the ox has a brownish appearance from the deposition 

 of a brownish pigment. Sinu- 

 ous outlines of endothelial 

 cells may be seen on the tra- 

 beculae, and branched cells of 

 the lymph sinus (fig. 223), 

 and even the follicular sub- 

 stance. It is continuous with 

 the endothelial lining of the 

 lymphatic vessels. 



3. Injection of the Lymph 

 Channels. Fill a hypoder- 

 mic syringe with a watery T' i_ M.C. L T 



Solution Of Berlin blue, force Fia 223 ._ Lyfn p h sinuses from the Medulla of a 

 the nozzle of the syringe into Lymphatic Gland. T' and T. Trabeculfe ; L. 



a small lymph gland of an 



ox, and inject the blue fluid 



haphazard into the gland. The blue passes into the lymph 



channels. Harden in alcohol. Make sections by freezing, stain 



them with picro-carmine, and mount in Farrant's solution. 



(L) The channels are filled with a blue mass, while the leuco- 

 cytes are red and the septa yellowish-red. The blue mass lies under 

 the capsule, and in the lymph paths around the trabecula. Notice 

 the difference in the distribution of the blue mass in the cortical 

 and medullary parts of the gland. If it be desired to study the 

 endothelium covering the trabeculae, inject the gland as above, but 

 with y 1 ^ per cent, silver nitrate, and harden in alcohol. 



4. Central Tendon of Diaphragm. Lave the central tendon of 

 the diaphragm of a newly-killed rabbit in distilled water. Place it 

 for an hour in .2 per cent, silver nitrate in a dark place. Remove 

 it, wash again, and place it for twenty-four hours in water contain- 

 ing a little alcoholic solution of thymol (10 percent.), or a drop 

 of carbolic acid to prevent the formation of fungi. Maceration in 

 water enables the endothelium on the surface to be readily pencilled 

 off. Mount it in balsam. 



(L) Examine the pleural surface with the naked eye or with a 

 lens, and a plexus of lymphatic vessels clear on a dark-brown 

 ground will be seen (fig. 224). The vessels anastomose, and lead 

 into narrow vessels, which run more or less parallel to each other, 

 and correspond to inter-tendinous spaces. 



(H) Observe the dilations and constrictions in the finer lymphatic 

 vessels, and their sinuous epithelium (fig. 225, L), and the com- 

 munications between the cell-spaces and the lymphatics. (Lesson 

 XL 12.) 



