2 4 



PHACTICAL HISTOLOGY. 



[XX. 



with logwood or logwood and eosin, and mount in balsam. Sections 

 may be stained first in acid-hsematoxylin and then counter stain 

 them with eosin. For the lymph-knots or germ-centres stain with 

 safranin and counter stain with picric acid. 



For fixing the sections on a slide, Gulland 1 uses a modification of 

 the capillary-attraction method of Gaule. The sections in paraffin 

 are placed in warm water as recommended by GaskelL 2 Float the 

 sections on to a slide, pour off the surplus water, and expose the 

 slide for several hours to a temperature under that of the melting- 

 point of the embedding paraffin. When dry remove the paraffin 

 by xylol and then stain the sections. They adhere to the slide by 

 capillary attraction. 



(L) Observe on the surface the stratified squamous epithelium, 

 and under it numerous round or oval aggregations of adenoid tissue 

 (fig. 227). These form but imperfect nodules. Pit-like recesses 

 are seen, lined by stratified epithelium, and into them mucous glands 

 sometimes open. 



(H) Trace some of the leucocytes of the adenoid tissue upwards 



JlQ. 227. Single Follicle of Tonsil, x 20. i. Cavity of follicle ; 2. Epithelium infil- 

 trated with leucocytes; 3. Adenoid tissue ; fi, 2, and 3. Follicles cut in various 

 directions,/! with a lymph-knot ; 4. Fibrous sheath; 5. Section of duct of mucous 

 gland ; 6. Blood-vessel. 



between the epithelial cells, so that the epithelial layer is at places 

 infiltrated with leucocytes. 



1 Jour, of Anat. and Phys., xxvi., 1891, p. 56. 

 * Quart. Jour. Micros. Sci., xxxi., 1891, p. 382. 



