240 THE SUPRARENAL BODIES. 



The general position and relations of the suprarenal bodies 

 have been fully given by Leydig and Semper, and I have 

 nothing to add to their statements. They are situated on 

 branches of the aorta, segmentally arranged, and extend on each 

 side of the vertebral column from close behind the heart to the 

 posterior part of the body-cavity. The anterior pair are the 

 largest, and are formed apparently from the fusion of two 

 bodies\ When these bodies are examined microscopically, their 

 connection with the sympathetic ganglia becomes at once ob- 

 vious. Bound up in the same sheath as the anterior one is an 

 especially large ganglion already alluded to by Leydig, and 

 sympathetic ganglia are more or less distinctly developed in 

 connection with all the others. There is however considerable 

 irregularity in the development and general arrangement of 

 the sympathetic ganglia, which are broken up into a number of 

 small ganglionic swellings, on some of which an occasional extra 

 suprarenal body is at times developed. As a rule it may be 

 stated that there is a much smaller ganglionic development in 

 connection with the posterior suprarenal bodies than with the 

 anterior. 



The different suprarenal bodies exhibit variations in struc- 

 ture mainly dependent on the ganglion cells and nerves in 

 them, and their typical structure is best exhibited in a posterior 

 one, in which there is a comparatively small development of 

 nervous elements. 



A portion of a section through one of these is represented on 

 PL XVIII. fig. 6, and presents the following features. Externally 

 there is present a fibrous capsule, which sends in the septa, im- 

 perfectly dividing up the body into a series of alveoli or lobes. 

 Penetrating and following the septa there is a rich capillary 

 network. The parenchyma of the body itself exhibits a well- 

 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 



1 There is a very good figure of them in Sempcr's paper, PL xxi. fig. 3. 



