HIDDEN PROCESSES 151 



seems to have the property of destroying 

 mucinoid material, probably absorbed, in a 

 more or less modified condition, from mucous 

 surfaces. At all events atrophy of the thyroid 

 body produces a peculiar disease known as 

 myxoedema, in which the cellular tissues are 

 infiltrated with a mucinoid matter, while there 

 are symptoms of an anaemia (deficiency of red 

 cells of the blood). This condition is much 

 modified or disappears on administering raw 

 thyroid, powdered thyroid, or the thyroidin 

 extracted from the organ of the sheep or 

 similar mammal. As curious nervous symp- 

 toms appear after removal of the thyroid it 

 may have other internal functions. 



81. The suprarenal bodies were at one time 

 thought to have to do with the formation 

 or modification of pigment, and possibly this 

 may be the case, but they are now known to 

 produce a chemical substance termed adrena- 

 lin, which has a specific action in stimulating 

 non-striated muscular fibre. Thus it stimu- 

 lates the coats of the arterioles, causing 

 their calibre to be very much diminished, 

 and as the heart still vigorously beats, the 



