XII. THE EVOLUTION OF MANKIND AND ITS FUTURE 431 



success. The company chose as its barometer the size of the policy 

 each man held, long considered an excellent key to earning power. As 

 the result it was found that an amazing parallel was present between 

 the average policy and height, indicating clearly that the richer a man 

 the taller his stature (118). It is well known that the increase in the 

 stature of Japanese is more striking in towns than in the country. 

 Dwarf horses have arisen on various islands where a limited food 

 supply was probably the most effective cause ; the pygmy elephant of 

 Malta and some other cases in animals may have had a similar origin. 



Another probable cause of lessening in the rigidity of the genes 

 may be the growth hormone itself. Overspecialization of animals 

 appears to be usually connected with the increase in the bodily size, 

 suggesting that growth hormone is required for the specialization. 

 The specialization, on the other hand, may not be achieved without 

 the decrease in the rigidity or the elasticity of a gene. Growth hormone, 

 therefore, may be essential for the lessening in the rigidity. The 

 effect of the hormone revealed in the establishment of unusual growth 

 may be a manifestation of the reduction of the genie rigidity itself, 

 since unusual growth may be unable without the loss of the rigidity. 



A stress causing a rapid change in animal characters appears to 

 exert stimulating effect upon hypophysis. Growth hormone may be 

 yielded in response to such a stress in order to achieve with ease an 

 adaptive change. If this conception is true, when a hypophysis-stimulat- 

 ing factor continues to exist with the continuous production of growth 

 hormone, the decrease in the rigidity will be unlimitedly pushed 

 forwards, thus the speed of a change directed to the destruction being 

 accelerated. 



4. Viruses, the Fatal Enemy of Man 



The loss of the rigidity in the genes will be revealed in the 

 protoplasm as the acquisition of an easily changeable character. Such 

 a character of the protoplasm, on the other hand, may be nothing but 

 a high susceptibility to various viruses, since the structural change 

 of protoplasm by a virus is no more than the occurrence of the infec- 

 tion with the virus. If the protoplasm is provided with a strong 

 reversibility, virus structure will soon be expelled and the protoplasm 

 will recover its normal state even when the protoplasm is once affected 

 by the virus. 



Cancer is a disease presumably resulting from the loss or the reduc- 

 tion of the rigidity in the protoplasm including genes, a disease in 

 which genes are coming out of order leading to the abnormal reduc- 



