LESSON XVIII. 

 • THE LYMPHATIC SYSTEM. 



A. Lymphatic Glands. 



1. Prepake vertical sections of a rabbit's Peyer's 

 patch which has been hardened in ammonium 

 bichromate 5 p.c, and stain them with carmine. 

 When stained, mount a section at once, to observe 

 the immense number of leucocytes; shake up 

 the others in a test-tube with water. Look at 

 them under a low power to see if the leucocytes 

 are for the most part shaken out ; if so, mount 

 them in glycerine. Select a comparatively iso- 

 lated folUcle, and obsei-ve 



a. The adenoid tissue of the follicle (cp. Less, 

 xvit. § 1, a (7)), continuous more or less 

 distinctly with the neighbouring adenoid 

 tissue, and resembling it in all respects ex- 

 cept that the fibres are, as a rule, finer, and 

 the meshes smaller. 



h. Around parts of the follicle, narrow spaces 

 between it and the surrounding tissue ; these 

 represent the lymph-sinus on the outside of 

 the follicle. 



