126 THE GLANDS REGULATING PERSONALITY 



The latter occurs most regularly in the subadrenal types, the 

 former in the hyperthyroid. Both forms of reaction run parallel 

 to the different check or drive effects of the vegetative apparatus. 

 With too much drive, that is, too much thyroid, there is the 

 flushing reaction; with too little check, that is, with too little 

 adrenal, there is the whitening. These differences probably ex- 

 plain the emotional reactions of the face. In anger, for example, 

 some people become a dead white, others a fiery red. Whether 

 one will do one or the other may depend upon the relative pre- 

 dominance of the thyroid or of adrenal in the individual. 



In the distribution of fat beneath and throughout the skin all 

 of the endocrine glands appear to have a voice. The typically 

 hyperthyroid and hyperpituitary individuals tend to be thin, 

 as well also as those who have well-functioning or excessively 

 functional interstitial cells. In all of these the administration 

 of the respective internal secretions increases the burning up of 

 material in the body, and all of them have a higher rate of tissue 

 combustion than their confreres, with a subthyroid or sub- 

 pituitary keynote in their cell chemistry, or with insufficient in- 

 terstitial cell action. Generally the latter have a very dry skin, 

 the former a moist skin. With delayed involution of the pineal, 

 obesity results. 



The elasticity of the skin is another quality that varies with 

 the concentration in the blood of the internal secretions. Elas- 

 ticity of the skin, its recoil upon being stretched like a rubber 

 band, may be taken as a measure of the activity of all the 

 endocrine glands. For, as can be noticed especially upon the back 

 of the hand, the older a man grows, the less elastic becomes the 

 skin. In older people, raising the skin upon the back of the hand 

 will cause it to stand up as a ridge for a few seconds and then 

 slowly to return to the level of the surrounding skin. Whereas 

 in a youthful person it will quickly snap back into place. This 

 quality of elasticity of the skin is due to the presence in it of 

 the so-called yellow elastic fibres, cell products, with a resilience 

 greater than anything devised by man. The preservation of the 

 resilience is a function of the internal secretions. Thus, after 

 loss of the thyroid, the ridging effect characteristic of senility 

 can be produced in one young as measured by his years. It 

 has been said that a man is as old as his arteries, and also 

 that as he is as old as his skin. It might better be said that 

 he is as old as his elastic tissue, young when he is rich in it, old 

 when poor and losing it. And as elastic tissue and internal secre- 



