GLANDS. 481 



cells, and accounts for the fact, that when the vesicles are 

 broken up with needles, they are entirely reduced to fibrous 

 tissue. 



The contents of the vesicles consist of a fluid, containing 

 numerous granular nuclei of a rounded or oval form, as well 

 as of a few perfect cells, two or three times larger than the 

 nuclei, and the granules contained in which are very large, 

 presenting an oily aspect; between these two extremes of 

 size, other cells intermediate are met with : the larger are evi- 

 dently parent cells. (See Plate LXL figs. 9. and 4.) 



The fluid of the vesicles contains a good deal of oil, which 

 when the gland is slightly decomposed, is apt to collect in 

 them in the form of one or two large circular discs. 



The increase in the size of the gland in goitre is due to 

 an increased development of the vesicles and of their con- 

 tents. 



It is evident that each vesicle contains all the elements of 

 the gland, and that the entire organ is made up of an assem- 

 blage of many thousands of such vesicles or glands. (See 

 Plate LXL fig. 2.) 



SUPRA-RENAL CAPSULES. 



The supra- renal capsule bears some resemblance in structure 

 to the kidney, being divisible like it into a cortical and medul- 

 lary substance. 



It is made up of numerous simple and cylindrical tubes 

 closed at both ends, and formed of structureless basement 

 membrane ; these tubes are disposed in a vertical manner, one 

 extremity forming the surface of the organ, and the other 

 extending in an opposite direction, as far as the inner cavities 

 or Iacuna3 situated in the centre of each supra-renal capsule. 

 (See Plate LXII. fig. 3 a.) 



These tubes enclose elements of three kinds ; first, innu- 

 merable circular particles or molecules, which reflect the light 

 strongly, and which are of an oily nature ; of these the greater 

 part is free in the tubes, but a lesser proportion is en- 



Q Q 4 



