NORMAL AND PATHOLOGICAL GROWTH 163 



by the fine height and straight bearing of Missouri men. Yet, 

 several hundred students, classified on the basis of graded 

 height, seldom deviate outside the above limits. Any marked 

 deviation above this average in height may be classified as gi- 

 gantism, and a pronounced variation in the opposite direction 

 would be classified as dwarfism. 



In America there are many extreme cases of gigantism, as an 

 example, the "Denver giant" over 8 feet 10 inches in height, 

 or the Texas lad mentioned in the recent daily press who writes 

 me that he is 8 feet 1 inch tall and weighs 300 pounds at the 

 age of 19. These excessive heights are abnormal and are due to 

 very definite causes. 



Gigantism is primarily a defective or abnormal overgrowth 

 of the skeleton, in particular the long bones of the legs, arms, 

 hands, feet, etc. The long bones grow from three ossification 

 centers. One for each end, the epiphyses, and one for the shaft, 

 the diaphysis. When these centers of bone development fuse 

 then growth in length of the bone ceases. 



Excessive skeletal growth occurs in response to the over- 

 stimulation by substances produced in the anterior lobe of the 

 tiny gland at the base of the brain known as the pituitary. This 

 gland when overactive stimulates excessive growth of bone 

 and connective tissues, when underactive it retards growth and 

 the individual is small and infantile in appearance. The physio- 

 logical activity of the pituitary gland may under some condi- 

 tions be greatly accelerated. At such times it produces a greater 

 quantity of its secretion or hormone and this overstimulates the 

 growth processes in the skeleton. 



Causes of hypertrophy of the pituitary are not so readily de- 

 termined, but the effects on size and stature are clear cut and 

 distinct. In giants, an increase in function of the pituitary has 

 occurred at an early age, i.e., before the union of the three 

 growing centers of the long bones. The universal history of ex- 

 treme gigantism is that the excessive height was first observed 

 in early youth more often between the ages of 12 and 18, sel- 



