THE ANATOMY OF THE THRYOID GLAND 



179 



chial artery; the fluid pours into the sinus venosus and auricle 

 very freely before it has even reached the subclavian by way of 

 the hypobranchial artery. This is the case whether the fish has 

 been previously bled or not. This experiment would certainly show 



COTXiCOld 



A.lat- 



Fig. 6. Diagram of the hypobranchial arterial circulation in Squalus acanthias. 

 Lateral view. 



that the hypobranchial is of too small a caliber to supply the blood 

 necessary to fill the coronary arteries, and if it can not supply this 

 much it certainly is still less competent to supply blood for the 

 whole hypobranchial system, which T. J. Parker's description 



