GROSS ANATOMY 27 



teric plexuses and have been reported in association with 

 ganglia on the kidney, prostate, ureter, et cetera. 



In addition to the paraganglia a number of masses of chroma- 

 phil tissue are also developed in relation to the abdominal 

 sympathetic plexuses. Of these, the most prominent are the 

 aortic bodies (ZuckerkandPs bodies) which lie on either side 

 of the aorta at the origin of the inferior mesenteric artery. In 

 the new-born they are about a centimeter in length but de- 

 generate and gradually disappear (except under certain patho- 

 logical conditions) so as to be seen only microscopically from 

 puberty until the age of about forty. 



The carotid gland also forms part of the chromaphil system. 

 It is a bilaterally paired organ situated in close relation to the 

 bifurcation of the common carotid artery. It is oval or 

 wedge-shaped depending upon its position in relation to the 

 artery and is about 7 mms. long, and 2 to 5 mms. in diameter. 

 In appearance it is grayish, yellowish or brownish red. 356384 



The coccygeal body has been erroneously referred to by some 

 authors as a part of the chromaphil system. This body does 

 not, however, give the chromaphil reaction. 698 It cor- 

 responds to the caudal glomeruli of lower animal forms. 649 



The chromaphil tissue of mammals occurring in the para- 

 ganglia of the sympathetic trunk is homologous to the seg- 

 mentally arranged chromaphil bodies of the elasmobranchs. 

 The chromaphil bodies of the abdominal plexuses are, on the 

 other hand, formations peculiar to the higher vertebrates, while 

 the inclusion of chromaphil tissue within the capsule of cortical 

 tissue, as in the adrenal glands, is a development found only 

 in the mammalia. Although similar anatomically, it is ques- 

 tionable if all the component tissues of the chromaphil system 

 are functionally equivalent (cf. Chapter VI). 



The method for demonstrating the chromaphil tissue as 

 introduced by Stilling 596 and Kohn 357 consisted simply in ex- 

 posing the tissue to a solution of potassium bichromate and 

 subsequently washing and examining the tissue for brownish 



