126 



THE UNIVERSITY SCIENCE BULLETIN. 



portion of the gland, narrows down, and the thymus appears be- 

 neath the sternum as two slender, parallel ribbons of glandular 

 tissue. Once into the neck region, however, these two ribbons be- 

 come very much larger and diverge, passing anteriorly to the base 

 of the mandible, one on each side. In the thyroid region they 

 parallel each other closely, lying on opposite sides of the thyroid, 

 and thus fairly close to the median line. Then each passes from 

 here into deeper tissue and obliquely away from the median line, 

 ending behind the mandible. The thymus seems to be made up of 

 many small lobules, combined into larger lobes. The accompany- 

 ing sketch will give, perhaps, a clearer idea of the form of the 

 gland. 



■RiqK-t Lobe 

 of Thumvjis 



- Left ■ Lobe 

 \\ of Thumas. 



- Trachea 



Lun<^ 



T"horacia 



"Portion of I hijn-ius 



^ -x r* Heart 



Sketch 



of the 

 ThYMU5 "V vSiTU 



