206 THE PITUITARY, THYROID AND ADRENALS AS A SYSTEM. 



which we have traced to the thymus, are no longer produced 

 in the organism. Such an assertion is contradicted by consid- 

 erable clinical evidence and by the pathological phenomena of 

 the cases of acromegaly in which the thymus is not persistent. 

 There must be, therefore, a successor to the thymus capable 

 of continuing actively or passively its physiological functions. 

 Especially must this be the case since, as we have seen, impair- 

 ment of the functions of the thymus and of the adrenals un- 

 derlies the disorders of nutrition which inhibit the develop- 

 ment of the cerebro-spinal, nervous, and osseous systems 

 all structures involved in acromegaly. It would appear, there- 

 fore, that, if overactivity of the pituitary gland is the source 

 of acromegaly, this organ should assume at least some of the 

 functions of the thymus at puberty. 



That this conclusion is justified seems sustained by con- 

 siderable testimony; it would remove the obstacles that are 

 themselves as strongly supported by existing data. Gigantism, 

 for instance, can thus assume the apparent autonomy observed 

 in some cases. A persistent thymus overlapping an efficient 

 pituitary, plus adrenals that are necessarily overactive through 

 the extra stimulus which the additional organ procures, make 

 up a physiological trio fully capable of causing the additional 

 formation of cellular elements which excessive growth involves. 

 We know that when overgrowth is a feature of acromegaly it 

 mainly appears in adolescent subjects or young adults, while 

 it is the exception when the disease appears in middle-aged 

 subjects or later. Indeed, the stature of some of the latter is 

 sometimes shortened by scoliosis. Again, there is a marked 

 distinction between the forms of acromegaly observed during 

 youth or adolescence and that occurring after maturity: a 

 feature emphasized by Woods Hutchinson. 42 The overdevel- 

 opment of the former is comparatively symmetrical; the over- 

 growth in the latter mainly shows itself at the points of least 

 resistance: i.e., the extremities, hands, feet, nose, lower jaw, 

 etc. 



It seems probable, however, that, while Maximilian Stcrn- 

 berg's view that there are two forms of gigantism, the first 



"Woods Hutchinson: Loc. cit. 



