THE SUMMARY OF PART V 449' 



may lie in this, because the deficiency of food and also the irritable, 

 uneasy life peculiar to uncivilized life presumably exert upon hy- 

 pophysis counteraction against climatic factor. 



The want of food may result in adrenal insufRcience by counter- 

 acting against stimulating climate, and in addition nervous tension and 

 irritability attending on uncivilized, barbarous life may also counteract 

 against climate by stimulating some hormonal systems mainly thy- 

 roid. Because of the presence of such preventing factors, uncivilized 

 people may neither increase their stature nor become insusceptible 

 to tuberculosis even under the stimulating climate. However, with 

 the development of civilization these preventing factors are removed to 

 enable the stimulating climate to exert its full influence. 



During and immediately after the Second World War, Japanese 

 children were reduced in their height remarkably, suggesting strongly 

 that the want of food and nervous tension inhibited the production of 

 growth hormone. Even in peace time, country man is smaller than 

 town man, and students with high scholastic standing are generally 

 above the average in height. Moreover, children of a large family are 

 remarkably below in height than those of a small family. 



Excessive use of certain organs may lead to the enhanced secretion 

 of growth hormone, which m^ay presumably contribute to the rapid 

 development of organs continuously used. The speedy development of 

 an organ would be achieved by a swift change of the genie pattern, 

 and this swift change may be favoured by growth hormone. This 

 hormone, on the other hand, would promote the growth by causing a 

 swift change in genie pattern. Therefore, the vigorous production of 

 growth hormone resulting from the pituitary hyperfunction may 

 cause the lability of the structural pattern of genes, rendering the 

 protoplasm very unstable so that the susceptibility of the organism 

 to some viruses including cancer may be strikingly increased. 



It has actually been established that adrenocorticotrophic and 

 cortical hormones affect the course of some infectious diseases mainly 

 those caused by viruses including cancer to the disadvantage of the host, 

 whereas nutritional deficiency which inhibits the production of these 

 hormones is known to increase the resistance to viruses and cancer. 

 During a war, the incidence of tuberculosis may be strikingly increased, 

 but that of some virus diseases is declined. Children of a large family 

 show a great resistance to some viruses, and children in the country 

 are also less susceptible to the viruses than those in towns. The 

 same is the case with uncivilized and civilized people. 



The specialization of civilized people as revealed in the increase 

 in the stature may be ascribed to the structure of genes becoming 

 unstable as shown in the fact that their susceptibility to some viruses 



