AND PERSONALITY 



the infant of 1 1384. In the adult the weight of the adrenal 

 glands is approximately u grams, the ratio of the weight 

 of the adrenal glands to the body weight of the adult being 

 1 15,000. 



The thyroid gland in the fetus is smaller than the adrenal 

 glands. Dr. Quiring states that whereas the adrenal glands 

 weigh 8.6 grams at birth the thyroid gland weighs only 

 3.2 grams. This adrenal-thyroid relation becomes reversed 

 sometime before the twenty-first year, when the thyroid 

 gland weighs approximately 2^ times the weight of the 

 adrenal glands. 



In a comparative study of the thyroid and adrenal glands 

 in 747 wild animals in which data regarding different age 

 periods were available, Dr. Quiring and I found that the 

 adrenal glands were from 24 to 450 per cent larger in their 

 relation to the body weight in the infants than in the adults. 

 In the human being the adrenal glands in the newborn are 

 twenty-one times larger in their relation to the body weight 

 than in the adult. 



From the anatomical facts that during the third month 

 of human fetal life the adrenal glands are twenty-one times 

 larger in their relation to the weight of the fetus than are 

 the adrenal glands in the adult in relation to the adult body 

 weight and that even several months after birth the adrenal 

 glands in relation to the weight of the infant are smaller 

 than the adrenal glands in relation to the weight of the 

 fetus, we must conclude that there is a unique factor during 

 fetal life that is not present in adult life. The fact that the 

 adrenal glands are relatively larger in the young child and 

 in the adolescent than in the adult would also seem to 

 indicate that some extraordinary activities are present 

 during the first twenty-one years of life. 



The brain-to-body-weight ratio in the infant and the 

 young child is higher than the brain-to-body-weight ratio 

 in the adult. In our studies in comparative anatomy the 

 brain-to-body-weight ratio of the infant wild animals was 



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