338 INTERNAL SECRETION 



conditions, a reduction of the secretory elements is to be assumed. 

 This, however, is readily understood, if we remember the enormous 

 difficulty of estimating the functional activity of the different 

 structural elements; moreover, judging by experience in other 

 directions, it is by no means improbable that the specific function 

 of the tissue of a malignant tumour is similar to, and may be 

 even stronger than, the specific function of the normal tissue. It 

 is a by no means rare thing in acromegaly for the anomalies of 

 growth, after progressing to a certain point, to arrive at a stand- 

 still ; there may even be regression, followed later by cachexia 

 with regressive nutritional disturbance. It was upon these facts 

 that Tamburini founded his hypothesis. Finally, it must not be 

 forgotten that hyperfunction of the hypophysis is associated with 

 changes in the activity of other internal secretory organs, the 

 influence of which upon the general economy may continue, 

 though in a perverted sense, after the primary factor, the hypo- 

 physal hyperplasia, has either ceased to exist or has undergone 

 regressive changes. 



This latter possibility leads us to the question : What is the 

 primum movens in acromegaly ? From the nature of the evidence, 

 it appears unquestionable that the hypophysis is the site of origin 

 of acromegaly, and that the nature of the illness is dictated by 

 hypersecretion on the part of that organ. But the question as to 

 whether we are to regard the pathological condition of the hypo- 

 physis as primary, or merely as the secondary result of organic 

 affection in other parts of the body, remains unanswered. The 

 latter assumption is permissible, for numerous experiments have 

 shown that there is a physiological interrelationship between the 

 hypophysis and other internal secretory organs, namely, the 

 thyroid, thymus, suprarenals, and especially the sexual glands. 

 Moreover, pathological conditions of these organs are associated 

 with profound changes in the hypophysis. 



The interrelationship between the thyroid gland and the 

 hypophysis has already been described. Rogowitsch first showed 

 that thyroidectomy is followed by hypertrophy of the hypophysis, 

 and his finding is confirmed by all later observers. In the depart- 

 ment of human pathology, it has also been shown that, in myx- 

 tiedema and other related subthyroidic conditions, there is 

 frequently enlargement and pathological change of the hypo- 

 physis. Of the manner in which hypophysectomy in animals affects 

 the thyroid gland, we know only that Caselli found hypertrophy 

 of the entire thyroid apparatus. In the two cases which recovered 

 after hypophysectomy at Hochenegg's clinic, there was distinct 

 increase in the volume of the thyroid. Pineles emphasized the 

 clinical relationship between acromegaly and myxoedema, which 

 he believes to be shown, not only in the comparatively frequent 

 co-existence of the two conditions, but also in the similarity of 

 many of the symptoms and in the occurrence in acromegaly of 



