162 JEREMIAH S. FERGUSON 



accurate. The hj-oid sinus is shown to empty into the jugular vein 

 with a valve at the orifice. The anastomosis between the hyoid 

 sinuses is considered, but its relation to the thyroid gland is not 

 discussed; since no mention of the thyroid gland is made it would 

 appear that this important organ was either overlooked or ignored. 

 Unless one is specially looking for the gland, in the effort to sepa- 

 rate the muscles without injury to the venous channels the organ 

 is easily broken up, and once disintegrated its particles are readily 

 lost amongst the mass of muscular tissue. 



The tributaries of the hyoid sinuses are stated by Parker to 

 include the submental, posterior facial, internal jugular, and the 

 nutrient veins from the first hemibranch. 



Parker's description of the hypobranchial system follows that 

 of the ventral and dorsal aorta and begins with the subclavian 

 artery, which, he says, gives off the branchial and hypobranchial 

 arteries. Apparently he omits to mention the large lateral or 

 epigastric artery, whose course parallels that of the lateral vein, 

 though the beginning of the vessel is indicated but not named in 

 some of his figures. The hypobranchial artery described and figured 

 as a continuation of the subclavian, after giving off the antero- 

 lateral arter}^ — which I find to be distributed to the pericardium 

 and adjacent muscles — unites with its fellow of the opposite side, 

 passes forward 2 cm. in front of the conus arteriosus, and forms a 

 plexus from which are given off the coronary arteries posteriorly, 

 and anteriorly the median hypobranchial artery. The plexus com- 

 municates laterally by two commissural arteries on either side 

 with the longitudinal commissural vessels uniting the ventral 

 ends of the efferent branchial loops. One gathers from the descrip- 

 tion that the course of the circulation is from the subclavian artery 

 through the hypobranchial to the efferent branchial loops, a 

 direction which may be thus tabulated : 



branchial 

 hypobranchial 



coronary (paired) 



median hypobranchial (azygos hypobranchial) 



commissural (two pairs) 

 antero-lateral (paired) 



