XXVl] DUCTLESS GLANDS 205 



NOTES. 



Thyroid and Parathyroid. 



The cells of the thyroid are more columnar and the vesicles 

 smaller in young than in adult animals. To show columnar 

 cells the thyroid of a rabbit two to three weeks old may be 

 taken. Flat cells and large vesicles will be seen in the thyroid 

 of an adult dog ; and occasionally colloid substance between the 

 vesicles. In sections hardened in Flemming's fluid the colloid 

 substance stains with acid fuchsin, saffranin, picric acid and a 

 number of other reagents ; at times some cells (so-called colloid 

 cells) stain more deeply than others. 



In the fresh state, the cells are faintly granular, with some 

 distinct small globules. In the cat there are a number of these 

 small globules, forming more or less of an inner zone ; they may 

 be stained in specimens hardened in Flemming's fluid. In the 

 calf there are similar granules or globules, said to be pigment. 



The parathyroid lies on the trachea below the thyroid in the 

 rabbit ; it is more or less imbedded in the thyroid in the cat, 

 dog, and monkey. 



Pituitary Body. 



The pituitary body may be stained in bulk with hcema- 

 toxylin and eosin. In serial sections (cat), the glandular outer 

 coat of the posterior lobe will be seen to be continuous with the 

 anterior lobe ; in the dorsal part of this coat are distinct tubes 

 often filled with a homogeneous material; near the surface of 

 the anterior lobe a ciliated tube may be seen. 



Supra-renal Body. 



The cells of the medulla take a red-brown or brown tint with 

 chromic acid and chromic salts. 



The fat globules of the cortex, after treatment with osmic 

 acid, are readily soluble in xylol, soluble also though less readily 

 in chloroform and in bergamot oil (cp. p. 326). They become 

 however insoluble if the tissue is kept in alcohol for some time. 



