INFLUENCE OF THE DUCTLESS GLANDS ON THE GROWTH 15 



always dependent on a primary or secondary increase in function of the 

 suprarenal cortex, is as yet uncertain. 



As to the influence of the other ductless glands on the growth and confor- 

 mation of the body as yet little that is reliable is known. I shall only men- 

 tion that extirpation of the thymus glands leads to an inhibition of growth 

 that is later compensated. I shall treat of this further in the appropriate 

 chapter. 



The manner and means in which the ductless glands affect the growth is 

 only partly known. It may be said with certainty that the closure of the 

 epiphyses and hence a definite cessation in the normal growth occurs under 

 the influence of the sexual glands and indeed the interstitial glands; further, 

 that the development of the bone-nuclei and the growth in length of the bones 

 is strongly influenced by the thyroid gland and the hypophysis. I would 

 ascribe to the thyroid in this connection an influence at least as great as that of 

 the hypophysis. The influence of the latter seems to be very much over- 

 estimated, to the extent that it has been regarded as the dominating growth 

 center. The disturbances in growth produced by the thyroid differ im- 

 portantly from those produced by the hypophysis; I would especially at- 

 tach importance to the fact that in the thyroidal growth disturbances the 

 bones are thick [German word "plump" = coarse, thick, awkward]; in the 

 hypophysoprivic they are slender; the contrary may be seen in the increase of 

 function of these glands in early youth. In youthful Basedow's patients the 

 bones are slender; in youthful acromegalics they are thick and provided with 

 exostoses, and, so far as the disease is not complicated with associated eu- 

 nuchoidism, the bony processes are thickened. For the overestimation of 

 the significance of the hypophysis for the growth in length the Brissaud- 

 Meige's formula for gigantism should be held responsible. According to this 

 formula, gigantism is nothing other than an acromegaly of youth. It seems 

 to me, however, that in gigantism, at least in the earlier stages, there is found 

 mostly a hyperplasia also of other ductless glands, perhaps of the whole duct- 

 less glandular system; and especially the suprarenal cortex is often hyper- 

 plastic and, according to recent investigations, may influence in many ways 

 the clinical picture of gigantism as well as of acromegaly. I have pre- 

 viously mentioned that also premature development can be associated with 

 an increase of function in this organ, perhaps is regularly associated with it. 



Although here, too, very little is as yet known and explained in a satis- 

 factory manner as to the influence on the growth and bodily conformation 

 through the ductless glands, yet this influence is so striking that we may 

 conclude that a harmonious development of the body is not possible without 

 orderly functioning of the ductless glandular system. We as yet know 

 nothing as to the intimate processes in this kind of hormone action. Trophic 

 influencing of the nervous system may come into play in many of these 

 actions,' as the symmetry in such formative influences seems^to signify. 



