THE NERVOUS SYSTEM 159 



r arisen as to whether the origin of the disease 

 o be laid at the door of "nerves," whose rupture 

 ys havoc with the thyroid, or at that of the lat- 

 , which in turn affects the "nerves." An edi- 

 Lal in Endocrinology (1917) has this to say: 

 le work of Cannon demonstrates how complete 

 ;he cycle, and how difficult it is in a given case 

 tc ascertain whether the original cause was psychi- 

 cal or material. In no disease is this more evident 

 than in Graves's disease (which, you will remem- 

 ber, is a common form of hyperthyroidism ) . Here 

 a succession of nervous shocks may excite the adre- 

 nals until the thyroid is put into action, and hyper- 

 thyroidism arises. But again the stimulation of 

 the vagus (nerve responsible for sensation and mo- 

 tion) may come from so material a source as a 

 uterine myoma (a tumor of the womb) or other 

 pelvic structure as Hertzler points out. But the 

 outcome is the same: the thyroid becomes stimu- 

 lated until the threshold becomes permanently 

 lowered." 



That the origin may be a nervous one seems rea- 

 sonably clear from the experiences of the war. Dr. 

 Cobb, a captain in the Koyal Army Medical Corps, 

 writes : "It is a well-known fact that the syndrome 

 which we have hitherto called 'hyperthyroidism' 

 is frequently met with among the cases of func- 

 tional neuroses which arrive at the base hospitals 

 . . . the exophthalmos is not often marked, but 



