570 THE DUCTLESS GLANDS ENDOCRIN GLANDS 



histologic similarity to a sympathetic ganglion, Kohn proposes the 

 name, paraganglion caroticum. Its function is obviously similar to 

 that of the other organs of the chromaffin system, and probably chiefly 

 dependent upon the presence of adrenalin. 



The carotid gland is richly supplied with capillary blood-vessels and 

 small non-medullated nerve trunks. The capillaries are in intimate 

 relation with the glandular epithelium. 



VI. THE COCCYGEAL GLAND 



This small body 2.5 mm. in diameter (Eberth) was discovered 

 by Luschka in 1860. Its structure closely resembles that of the carotid 



gland. It usually con- 

 sists of several minute 

 groups of epithelioid 

 cells which are in re- 

 lation with the ter- 

 minal branches of the 

 middle sacral artery. 

 It is richly supplied 

 with broad capillaries 

 or sinusoids and hence 

 is also known as the 

 glomiis coccygeum. 



The parenchymal 



FIG. 490. FROM A SECTION OF THE COCCYGEAL GLAND cells of the organ are 



OF MAN. ovoid elements which 



Highly magnified. (After Sertoli.) are closely packed 



about the walls of the 



blood-vessels in groups or short columns inclosed by delicate sheaths 

 of connective tissue. The origin and function of these cells are un- 

 known. No chromamn cells have yet been certainly demonstrated. The 

 organ is embedded in the dense connective tissue at the tip of the 

 coccyx. Its general structure only suggests an internal secretory function. 

 According to Stoerck (Arch. mikr. Anat., Bd. 69, 1906), the cells 

 of the coccygeal body do not give the pheochrome reaction at any period 

 of life. They are believed to bear no genetic relation to the sympa- 

 thetic nervous system. Schumacher regards the epithelioid cells as 

 a transformation of the smooth muscle cells of the arterial vessels; 



