482 THE SOLIDS. 



closed in certain of the cells which are met with in the 

 tubes ; second, granular nuclei in large quantities ; and, third, 

 parent cells of considerable size, containing each several 

 nuclei intermingled with, and in part very frequently ob- 

 scured by a considerable number of the bright molecules 

 previously referred to. These parent cells do not appear to 

 have been hitherto characterised with any degree of precision. 

 (See Plate LXII. fig. 3 b.) 



The differences between the cortical and medullary portions 

 of the supra-renal capsule, depend principally upon the irre- 

 gular disposition of the tubes in the latter, the plexiform 

 arrangement of the vessels, and on the presence of numerous 

 parent cells containing more or less of colouring matter in 

 their interior. It is these cells which impart to sections 

 of the gland the dotted appearance so commonly observed in 

 its medullary portion. (See Plate LXII. fig. 3.) 



The vascular distribution in the supra-renal is very simple. 

 On the surface of the organ we have a very beautiful plexus 

 of capillaries, the pentagonal and hexagonal meshes of which 

 lie in the intervals between the extremities of the tubes ; in 

 the tubular part the vessels, both veins and arteries run in 

 straight lines between the tubules, terminating, on the one 

 hand, in the plexus on the surface, and, on the other, in the 

 central plexus. (See Plate LXII. fig. 1. 5.) 



The supra-renal is an organ which varies greatly in dif- 

 ferent subjects ; in some the proportion of granules is much 

 greater than in others ; in others again, the central lacunas 

 are occupied with a whitish-looking substance, which, on 

 examination, is found to consist of granular nuclei arranged 

 in irregular masses, but in which sometimes we can detect a 

 tubular disposition : in these cases we encounter from without 

 inwards, three substances ; cortical, medullary, and then lastly, 

 the central substance just described. 



The capsule of the supra-renal is often laden with fat, 

 which totally obscures the plexus on the surface of the 

 organ. 



The parent cells, when filled with oily molecules, bear a 

 close resemblance to the cells of a sebaceous gland, between 



