AND PERSONALITY 



independent thyroidized ancestor or from the adrenalized 

 ape? 



One important fact mav have a bearing on this query. 



4 Vagus nerve 



Adrenal gland - - 



Renal artery 



Aortic plexus 



Inferior mesenteric artery- 



Greater splanchnic nerve 

 Coeliac artery 

 Coeliac ganglion 



Superior mesentenc 

 artery 



Abdominal sympathetic 

 chain 



FIG. 27. The sympathetic nervous system of the carnivore (polar bear). 



This fact is in accord with HaeckePs law of ontogenetic and 

 phylogenetic recapitulation. In accordance with this law, 

 during fetal life animals recapitulate their ancestral past. 

 In the human fetus the adrenal glands are far larger than 

 the thyroid gland. This is the adrenal-thyroid pattern of 

 the ape. Following birth, the adrenal glands in man, relative 

 to body weight, become smaller, and the thyroid gland, 

 relative to body weight, becomes larger until about the 

 twelfth year, when they approximate each other in size. 

 Following this period, the thyroid gland continues to be- 

 come larger and the adrenal glands smaller until about the 

 twenty-first year, when the adult human formula is estab- 



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