Vascular System of the Thyroid Gland. 481 



branches which penetrate the gland. In a certain specimen the total 

 number of these branches from both anterior and posterior branches 

 was nine. These branches plunge into the gland and immediately 

 give oflf branches which run in various directions, some attempting 

 to gain the periphery of the organ, others running still deeper towards 



Fig. 2. — Gross blood supply of cat's thj-roid. X •^• 

 A. — Artery. V. — Vein. P. — Parathyroid gland. 



the center. These arteries of the second order surround definite di- 

 visions of the gland and give off no branches, as a rule, to the follicles. 

 The veins follow more or less the same course, but show frequent 

 anastomoses. 



The course of the arteries to the cat's thyroid is somewhat similar 

 to that of the dog. The superior thyroid artery, however, gives off a 



