48 ENDOCRINE GLANDS 



to discover a triple action: substitute, homo stimulating 

 and symptomatic. 



The substitute action consists in that the extract which 

 is administered substitutes its action for that of the deficient 

 organ. In congenital myxedema due to agenesis of the 

 thyroid, the extract takes the place of the absent thyroid. 



The homo stimulating or auto restorative action is also 

 easily understood; if the extract is administered when 

 the gland is only partly destroyed it can help in the re- 

 building of the organ and stimulate its function. This is 

 so in quite a few cases of thyroid insufficiency. 



To these two modes of action which can be termed spe- 

 cific, we can add a third which we must always keep in 

 mind when we are watching the effect of organo therapy. 

 An extract of an organ, like all other organic or mineral 

 medication, has a pharmacodynamic action peculiar to it. 

 As such it can be employed symptomatically to bring out 

 new symptoms or suppress pathological ones; the pituitary 

 furnishes an example of this type of action. We use pitui- 

 trin to accelerate labor or to increase intestinal peristalsis. 

 Basing himself on the symptomatic action of these extracts, 

 Gley has very rightly criticized the conclusions which are 

 reached on the action of certain extracts of organs. In 

 spite of this, symptomatic organo therapy has a big field 

 of action and thyroid extract in small doses has shown its 

 value in a multitude of cases. 



It seems difficult, however, in the great majority of 

 cases, not to believe in the substitute or homo stimulat- 

 ing effect of organo therapy. The recent investigations 

 of J. J. Huxley on the acceleration of growth by means of 

 very small doses of thyroid to tadpoles, his investigations 

 on the axolotl of the salamander under the influence of , the 

 same medication show how pronounced is the action of 

 thyroid on the phenomenon of growth. This action 



