HISTOLOGICAL DEMONSTRATIONS. 107 



layer of squamous epithelium. The large vessels, e.g. the 

 thoracic duct, have a structure similar to veins. 



171. Study the puncture method of injecting lymph- 

 atics described in 344. 



Klein's memoir on The Anatomy of the Lymphatic System, part i., 

 London, 1873, may be advantageously consulted by the advanced 

 student. 



BLOOD GLANDS. 



172. Lymph. Gland. The methods of preparing 

 lymphatic glands in the fresh condition, and after injection 

 with silver nitrate, have already been described ( no, in). 



Examine the section of lymphatic gland already pre- 

 pared (n o). 



(L.) The fibrous capsule sends into the interior numerous 

 trabeculse that are membranous in the cortex, and cord- 

 like in the medulla. These trabeculae may be seen cut 

 longitudinally and transversely. Contiguous with the capsule 

 and the trabeculae, there is everywhere a somewhat clear 

 space, the lymph sinus. From the capsule and trabeculae 

 a loose adenoid tissue extends across the sinus. The spaces 

 amidst the tissue elements constitute the lymph path 

 continuous with the afferent lymphatics through the cortex, 

 and with the efferent lymphatics through the hilus of the 

 gland. The lymph sinus everywhere encloses a ramifying 

 mass of " follicular tissue," consisting of a somewhat con- 

 densed adenoid tissue closely packed with lymph corpuscles. 



(H.) The fibres of the trabeculae. The loose adenoid 

 tissue of the lymph sinus, with probably here and there a 

 lymph corpuscle not shaken out of the spaces ( no). 

 The follicular tissue, with numerous lymph corpuscles. 

 The corpuscles are identical with the smaller white blood 

 corpuscles. They appear to be produced in the follicular 

 tissue, and to pass from thence into the lymph stream. 



Examine also (L. and H.) a section of silvered lymphatic 

 gland prepared as stated in in. 



173. Spleen. Methods. a. The spleen may be pre- 

 pared by hardening in chromic acid and alcohol as described 

 in ii. Sections may be readily made with the hand, or 



