00 BLOOD GLANDS. 



Spleen, injected. Cat. (Blue gelatin mass. p. 2 (d), s. 24, c P., 

 m. B.) (Z) Trace the blood-vessels through the trabeculse into 

 the splenic bodies and observe that the arterioles penetrate to 

 their interior, give off a few capillary branches which run to the 

 surface of the bodies, and there discharge their contents into the 

 general space of the pulp. The splenic bodies thus form rounded 

 islands of almost non-vascular pulp, surrounding the terminations 

 of the arteries. (Peri-angial lymphatic nodules ?) 



Thyroid. Man or Sheep, (p. 10, s. Saffranin in aqueous sol., 

 c. P., m. B.) (L) The organ is lobulated with loose connective 

 tissue between. The spherical vesicles which make up the 

 substance proper of the gland are lined by cubical epithelium, 

 the nuclei of which are visible with this power. The vesicles 

 are filled with a structureless substance, Colloid. (H) Examine 

 the epithelium and the disposal of the colloid which can be 

 frequently traced between its cells. Detached cells in the colloid. 



Thymus. Child, (p. 12, s. 22 & 24, c. P., m. B.) (L) The lobules 

 are separated by scanty areolar tissue. The substance proper- 

 looks uniformly granular with the exception of small round islands 

 stained pink, HassaWs corpuscles. (H.) The substance proper 

 consists of delicate adenoid tissue crowned with cells. The small 

 Hassall's corpuscles are hests of concentrically packed flattened 

 cells. The larger ones exhibit the same arrangement at their 

 periphery, whilst the interior is full of larger rounded cells, the 

 outlines of which are not always very distinct. These bodies are 

 regarded as hypoblastic relics. 



Thyroid, parathyroid and thymus of Kitten, (p. 3, s. 22 & 24, 

 c. P., m. B.) (Z) The partially developed thyroid shows besides 

 the vesicles masses of interstitial cells in which the gradations of 

 vesicular formation are recognisable. Small quantities of colloid 

 appears amongst the cells, which are gradually thrust apart and 



