HOW GLANDS INFLUENCE THE NORMAL BODY 127 



tions stand in the relation of created and creators, or at least 

 preserved and preservers, a man may be said to be as old, that 

 is as young, fresh and active as his ductless glands. 



The Hair 



There is no characteristic of the human body, except perhaps 

 the teeth, more influenced in its quality, texture, amount and 

 distribution than the hair. And again, each of the glands of 

 internal secretion plays a part, but most importantly the thyroid, 

 the suprarenal cortex and the interstitial sex glands. All con- 

 tribute their specific effect, and the blend, the sum of the addi- 

 tions and subtractions constituting their influences, appears as a 

 specific trait of the individual, a trait so significant as to be 

 used by the professionals absorbed in the study of man, the 

 anthropologists, as a criterion of racial classifications. 



Some acquaintance with the history of the normal growth of 

 hair is necessary to its understanding. There develops during 

 the life of the fetus within the womb a curious sort of wooly hair 

 everywhere over the entire body (excepting the palms and soles 

 which remain hairless throughout life) , remarkably soft and flut- 

 tery — the lanugo. At about the eighth month of intra-uterine 

 existence, a good deal of this lanugo is lost, to be replaced on the 

 head and eyebrows by a crop of thick, coarse, pigmented real 

 hair. So it happens that at birth the infant's hair is a queerly 

 irregular growth, a mixture of what is left of the general lanugo 

 development, and the localized patches of the more human hair. 

 Until puberty this children's hair remains the same, although at 

 times, particularly after dentition, and after infectious diseases 

 which undoubtedly alter the relations of the internal secretions, 

 changes of color and texture occur. Then, with sexual ripening, 

 there appear in males the so-called terminal hairs, over the 

 cheeks and lips and chin, and, in both sexes, in the folds under 

 the shoulders and over the lower abdomen, the hair which might 

 be distinguished as the sex hair in contradistinction to the juve- 

 nile hair of the head, the extremities and the back. 



Now the smoothness of the face in children is connected with 

 the activity of the thymus and pineal glands. Among individuals 

 in whom the juvenile thymus persists after puberty, no growth 

 of hair occurs on the face, and in precocious involution or destruc- 

 tion of the pineal, hair appears on the face and in other terminal 

 regions in children of six or less, a symptom classical in the child 



