172 GROWTH 



differentiate or develop to a maximum and retrogress each by an 

 independent curve of its own. Hence the sum of the hormonal 

 influences varies from period to period in the life cycle. 



4. When for any reason there is a profound augmentation, or 

 an extreme decrease in the amount, of any particular internal 

 secretion, the result on the body as a whole will be the produc- 

 tion of an abnormal curve of growth. These abnormalities may 

 range from the extreme amazonian stature of gigantism to the 

 pigmy in dwarfism, from the slender, nervous, and cadaverous 

 body of the hyperthyroid to the overfat and infantile form of 

 pituitary distrophy, from the masculine and bearded form of 

 the woman with adrenal tumor to the atrophy and retarded 

 nervous and physical development of the congenital cretinous 

 hypothyroid. 



5. A certain amount of activity and normal degree of physio- 

 logical fatigue favors a healthy energetic body and its processes 

 of growth. Lethargy is unfavorable since the stimulus to physio- 

 logical compensations is lacking. Overfatigue and exhaustion 

 are destructive to vitality, injure the tissues, debase metabolism, 

 and retard growth. 



6. Finally, there are the perverted growths derived from 

 various tissues and organs and which are entirely outside the 

 range of orderly physiological variation of organ form or 

 bodily development. These are the pathological tumors, either 

 benign or pathogenic in nature, which produce extreme devia- 

 tions or distortions in growth types. In fact, bodies with such 

 perverted form are never taken into consideration in the usual 

 measurement and study of growth processes, or in the construc- 

 tion of growth curves. The extremes of these types, the malig- 

 nant cancers, when unrestrained by artificial methods lead 

 quickly and directly to the destruction and death of the indi- 

 vidual. 



