116 IOWA ACADEMY OF SCIENCE Vol. XXV. 1918 



enveloped by connective tissue covering. They now take a posi- 

 tion laterad to the second aortic arch. 



The two epithelial bodies of either side are easily exposed in 

 the adult by gross dissection. They lie embedded in the con- 

 nective tissue on the side of the neck in the region just below the 

 thymus just eaudad to the carotid gland, although their position 

 may vary slightly in different individuals. 



The blood supply of these small epitbelial bodies is from the 

 small twig-s from the second aortic arch and from the external 

 carotid artery, and they are innervated by a small ramus from 

 the vagus nei've. 



Department of Zoology, 

 Iowa State College 



