RECIPROCAL ACTION OF THE DUCTLESS GLANDS 9 



stress on. Naturally this is also true in a clinical sense. Practically nobody 

 confuses a typical myxedema with typical hypophysial dystrophy. The 

 extirpation of the parathyroid glands increases the excitability of the vegeta- 

 tive nerves, extirpation of the thyroid diminishes it; the mechanism, however, 

 as I shall show later, is different. It is true that the tetany of the parathyro- 

 privic animal runs a milder course (after associated or subsequent thyroidec- 

 tomy), because on account of the absence of the secretion of the thyroid 

 gland the excitability of the vegetative nervous system is diminished, but 

 nevertheless the tetany is not thereby prevented. 



Now, as to the pathological correlations! These are furnished by the 

 ductless glands' membership in the same system. Diseases which affect one 

 gland often attack very commonly other ductless glands, or a disease process 

 may affect simultaneously several ductless glands, or the entire ductless 

 glandular system. By pathological correlations I understand the conceal- 

 ment, intensification, or modification of symptoms due to the alteration of 

 function of one kind of ductless gland through the presence of disease in an- 

 other. This may also be shown experimentally. I have already mentioned 

 that extirpation of the thyroid gland diminishes the excitability of the vege- 

 tative nerves, while that of the parathyroids increases it. We observe that 

 the glycosuric action of adrenalin, which is diminished after extirpation of 

 the thyroid gland, is not diminished on simultaneous extirpation of the para- 

 thyroid gland and may even be somewhat intensified. Another example: 

 Extirpation of the thyroid gland raises the assimilation limits for carbohy- 

 drates and reduces the protein exchange during fasting. Extirpation of the 

 pancreas reduces the assimilation limits very strongly and increases the pro- 

 tein exchange during fasting. Simultaneous extirpation of the thyroid gland 

 and pancreas produces indeed a diabetes; this, however, pursues a milder 

 course to the extent that the increase of the protein destruction is not so high 

 and the diminution in weight does not progress so rapidly. Therefore, 

 there has occurred a diminution of an otherwise increased metabolism. 



Now some examples from human pathology. 



Thyroid gland and the anterior lobe of the hypophysis show in many 

 respects much similarity; as, for example, in a phylogenetic respect both were 

 formerly glands with external secretion. They show similarity in morpho- 

 logical structure, and in many respects also in their physiological activity. 

 For example, young animals deprived of their thyroid gland or of their 

 hypophysis remain backward in growth, show diminution of the vegetative 

 processes, etc. Often both glands become diseased simultaneously. In- 

 deed, in acromegaly the development of a Basedow's struma is not unusual, 

 and in the later stages of acromegaly the thyroid may degenerate, with 

 attendant myxedema symptoms, as Pineles has described. In the cretinic 

 degeneration there is found not uncommonly both a goitrous degeneration 

 of the thyroid gland and degeneration of the glandular hypophysis. A 



