194 ELEMENTARY PHYSIOLOGY. [XVIII. 



7. Limiting the follicles and medullary 

 cords may usually be seen a fine line 

 with nuclei at intervals, indicating the 

 flat cells bounding the lymph channel. 



. The adenoid tissue of the follicles and 

 cords, with finer fibres and smaller meshes 

 than that of the lymph channels; unless 

 the section has been well shaken this 

 will be largely hidden by leucocytes. 



5. Examine sections of glands with the blood-vessels 

 injected. 



The arteries enter at the hilus surrounded by 

 connective tissue and branch in the trabeculae 

 of the gland. From the smaller of these branches 

 fine arteries run to the follicles and medullary 

 cords and form ija them a capillary network. 

 The veins have a distribution similar to that of 

 the arteries. 



B. SPLEEN. 



1. Take the spleen of a cat which has been hard- 

 ened in ammonium bichromate 5 p. c. and cut 

 out a piece at right angles to the long axis of 

 the spleen. Prepare sections of this with the 

 freezing microtome (cp. Appendix) or if that is 

 not available take a portion of the piece, imbed, 

 and cut by hand. Stain .some sections with 

 picrocarmine and mount in glycerine. Observe 

 under a low power 



