CHAPTER XII. 



SUPRA-RENAL CAPSULES THYROID GLAND THY- 

 MUS GLAND. 



SUPRA-RENAL CAPSULES. 



IN sections of the supra-renal capsules, through 

 their thickest part, and at right angles to the long 

 axis of the organ, we see with the naked eye two 

 distinct layers ; a tolerably firm, yellowish, striated 

 cortical layer of considerable thickness the cortex, 

 and a narrower central, yellow or reddish portion 

 the medulla. Between the two, or rather at the 

 inner side of the cortical portion, a more or less dis- 

 tinct brown zone is seen. 



If we examine thin sections microscopically, we 

 find that the organ is enclosed in a firm connective- 

 tissue capsule in which are numerous elastic fibres 

 and smooth muscle-cells. From this capsule, deli- 

 cate converging connective-tissue bands or septa, 

 similar in structure to the capsule, pass inward, and 

 being joined together by delicate transverse bands 

 or trabeculse, divide the cortex into a multitude of 

 variously shaped chambers. In the periphery, just 



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