THE SUPRARENAL BODIES. 471 



marked distinction in the majority of instances into a cortical 

 and medullary substance. The cortical substance is formed of 

 rather irregular columnar cells, for the most part one row deep, 

 arranged round the periphery of the body. Its cells measure 

 on about an average '03 Mm. in their longest diameter. The 

 medullary substance is more or less distinctly divided into 

 alveoli, and is formed of irregularly polygonal cells ; and though 

 it is difficult to give an estimate of their size on account of 

 their irregularity, "O2i Mm. may be taken as probably about 

 1 the diameter of an average cell. The character of the cortical 

 and medullary cells is nearly the same, and the cells of the two 

 strata appear rather to differ in shape than in any other essential 

 point. The protoplasm of both has a markedly yellow tinge, 

 giving to the suprarenal bodies a yellowish brown colour. The 

 nuclei are small compared to the size of the cells, being about 

 009 Mm. in both cortical and medullary cells. In the anterior 

 suprarenal body there is a less marked distinction between the 

 cortical and the medullary layers, and a less pronounced yellow 

 coloration of the whole, than in the posterior bodies. The 

 suprarenal bodies are often partially or completely surrounded 

 by a lymphoid tissue, which is alluded to in the account of their 

 development. 



The most interesting features of my sections of the anterior 

 bodies are the relations they bring to light between the sympa- 

 thetic ganglia and the suprarenal bodies. In the case of one of 

 the posterior suprarenal bodies, a small ganglion is generally 

 found attached to both ends of the body, and invested in the 

 same sheath ; in addition to this a certain number of ganglion 

 cells (very conspicuous by their size and other characters) are to 

 be found scattered through the body. In the anterior suprarenal 

 bodies the development of ganglion cells is very much greater. 

 If a section is taken through the region where the large sympa- 

 thetic ganglion (already mentioned) is attached to the body, one 

 half of the section is composed mainly of sympathetic ganglion 

 cells and nerve fibres, and the other of suprarenal tissue, but 

 the former spread in considerable numbers into the latter. A 

 transverse section through the suprarenal body in front of, or 

 behind this point, is still more instructive. One of these is 

 represented in PI. 19, fig. 7. The suprarenal tissue is not 



