FOREWORD Xlll 



functional activity of the gland beyond all question. Again it is urged that 

 it is difficult to conceive of overfunction as resulting from disease, which 

 might rather be expected to impair the activities to a greater or less extent. 



As against this it may be urged that it is equally hard to imagine a per- 

 version of the metabolic changes into new lines, other than those in which the 

 several protein fractions, and even the several carbohydrates, are normally 

 dealt with, stage by stage, by specialized enzymes. 



The more the internal secretions are studied the more clearly it is being 

 realized how wide is the field of their activities. We are learning that, in 

 addition to the control of metabolism, or rather in virtue of that control, the 

 endocrine glands exert immense influence upon growth and development; 

 and their their hormonic functions are exercised now in the direction of stimu- 

 lation, and now in that of restraint. Indeed it is not possible to conceive 

 of a control which is wholly one-sided; the controlling agent must be able to 

 curb as well as to urge on. So we are led to think of inhibiting as well as 

 exciting hormones, if that term may be so perverted from its literal meaning. 



In addition to our more exact knowledge, so encouraging in its progress, 

 although as yet so incomplete, of the work of the individual glands, we begin 

 to see evidences of an interaction of the organs of internal secretion, as mem- 

 bers of a group of immense influence, a hormonpoietic system. Here we are 

 stepping on to far less firm ground than we have hitherto trodden, and we 

 need to move with caution lest our hypotheses carry us further than our facts 

 warrant. Yet the evidence is at the least highly suggestive. We see how 

 removal of a single gland, by operation or disease, is followed by changes in 

 other glands of the group changes which are best explained by removal 

 of a wonted stimulus or withdrawal of a regulating control. 



Moreover there is evidence, as Claude and Gougerot were the first to 

 point out, that the various glands of internal secretion may be attacked simul- 

 taneously by a morbid process which is described as pluriglandular sclerosis. 

 Where this is the case the clinical picture presents elements of the several 

 syndromes which result from depression of function of the individual glands 

 of the group. Thus there are suggestions of hyperthyroidism, of pituitary 

 defect, of genital hypoplasia, and of Addison's disease, side by side in the 

 same patient. 



The interrelation of the endocrine glands and the nervous system is yet 

 another subject full of interest, and which receives full consideration in Pro- 

 fessor Falta's pages. How close is the control exerted by the vegetative 

 nervous system over the organs of internal secretion is brought home to us 

 when we consider such phenomena as puncture glycosuria. It may now be 

 taken as proven that the impulse conveyed to the adrenals by the splanchnic 

 nerves excites a temporary excess of secretion of these glands, and to this the 

 excretion of sugar is due. Thus it is suggested that not a few phenomena, 

 attributable to nervous impulses, are produced through the instrumentality 



