304 INTERNAL SECRETION 



character of this organ is expressed by the fact that, in the new 

 anatomical terminology, its designation was glomus caroticum. 



A. Kohn's (1910) minute histological investigations have com- 

 pletely elucidated the systematic position occupied by the carotid 

 organ. It is essentially composed of a largish agglomeration of 

 groups of chromaffine cells, and is traversed by a considerable 

 number of nerve fibres, the majority of which are without medulla, 

 and in which the cell balls and single ganglion cells are situated. 

 The organ is extremely vascular and the structure and arrange- 

 ment of the vessels are not in any way characteristic. Its pri- 

 mordial beginning is in embryonal ganglion cells of the inter- 

 carotid sympathetic nerve plexus. According to Kohn, the most 

 fitting name for the organ would be " paraganglion inter- 

 caroticum," and it should be included in the group of the 

 paraganglia, which he regards as members of the sympathetic 

 nervous system. But, as we have previously shown, the para- 

 ganglia form part of the adrenal system, and the paraganglion 

 intercaroticum cannot be classed separately from these. 



The coccygeal body (glomus coccygeum) was termed by 

 Luschka (1859) glandula coccygea, and was described by him as 

 a reddish yellow body of about the size of a small pea, situated 

 at the tip of the os coccyx and depending from the terminal 

 branches of the medial sacral artery. Luschka himself held that 

 this organ " might prove to be an integral portion of the sym- 

 pathetic nervous system, but that in the meantime, owing to 

 certain external characteristics, it was expedient to include it in 

 the mixed company of the ductless glands." And there the so- 

 called coccygeal gland has remained. The structural analogy 

 between this organ and others of the same group (hypophysis 

 cerebri, glandula carotis, suprarenal) has frequently been pointed 

 out. Waldeyer compared the round cells of the interstitial con- 

 nective tissue of the testis with the coccygeal and carotid glands, 

 and classed them together under the name of perithelial organs. 



Not only is there a similarity of structure between the carotid 

 and the coccygeal glands, but, according to Jacobsson, they also 

 resemble one another in their histogenetic relationship to the 

 sympathetic. According to Kohn, the carotid and coccygeal 

 glands are only the terminals of the continuous paraganglion 

 chain by which the sympathetic is accompanied. Schapper ex- 

 pressed the same view. 



And yet O. Stoerk (1907) showed that the cells of the 

 coccygeal gland do not react to chromium during either fcetal 

 or post-fcetal life ; and further, that they probably have a genetic 

 connection with the media of the vessels. According to Stoerk, 

 moreover, the coccygeal gland has no developmental relationship 

 to the sympathetic ; the structures which Jacobsson identified with 

 the primordial beginnings of this body have no connection with 

 it whatever, but are in reality young chromaffine bodies. 



