212 THE PITUITARY, THYROID AND ADRENALS AS A SYSTEM. 



sidered as compensative. Nor can enlargement found post- 

 mortem in cases of goiter, exophthalmic goiter, etc., be re- 

 garded as the result of ante-mortem vicarious excessive work, 

 since the hypertrophic process may have occurred during a 

 primary stage of overactivity and the pituitary have remained 

 in its enlarged condition, though perhaps histologically modi- 

 fied. Thus, in his analysis of 36 cases of acromegaly in which 

 the relative conditions of thyroid and pituitary were noted, 

 Hinsdale found that, while the pituitary was diseased in all, 

 13 thyroids were hypertrophied, 11 were atrophied, and 12 

 were normal. Even cases of myxcedema in which an enlarged 

 pituitary is found prove nothing, since the enlargement may 

 have occurred before the myxcedematous process, along, per- 

 haps, with unnoticed symptoms, the adrenals having soon lapsed 

 into insufficiency and reduced nutrition of the thyroid tissues: 

 the starting-point of the myxcedema. 



Of great value in this connection are the results observed 

 after experimental extirpation of the thyroid gland in animals, 

 especially if analyzed through embryological data. Thus, 

 Eogowitsch, among other investigators, noted enlargement of 

 the anterior lobe after extirpation of the thyroid in animals. 

 If the fact, pointed out by Andriezen, that both the thyroid 

 and the pituitary originate from a common region, the ecto- 

 derm of the primary oral cavity, is coupled with the view herein 

 advanced, that the thyroid supplies a substance which directly 

 stimulates the adrenals, these experimental results may easily 

 be accounted for. Indeed, to stimulate is to energize, i.e., to 

 enhance the tone of organic structures; to remove the thyroid, 

 therefore, is to eliminate the tone-giving function of the ad- 

 renals; the pituitary, especially the anterior lobe, being an 

 exceedingly vascular organ, relaxation of its vessels means 

 passive engorgement, followed by the enlargement observed 

 by Rogowitsch and others. Under these conditions it becomes 

 apparent that a morbid change in the thyroid may implicate the 

 pituitary without bringing compensation into the process. 



Indeed, a similarity between the secretions of these two 



organs is negated by the strongest kind of evidence besides 



that already adduced. Iodine, for instance, being undoubtedly 



' the main constituent of the thyroid secretion, and phosphorus 



