336 TAKASHI HAYASHI AND MASAO ARAREI 



was eating a plum. And that of one person was +0.29 g when 10 persons 

 were eating plums. We had a similar case for the lunch. It was —0.18 g 

 when 10 persons were eating lunch, the same as in the case of chocolate. 

 This time we determined that of 10 persons when another 10 persons were 

 eating lunch. The external conditioned reflex averaged +0.32 g. 



What does the above mean ? To interpret the quite unexpected results, 

 we made a temporary hypothesis that in the case of a food which children 

 were fond of, the external induction would be positive. On the other hand, 

 in the case of a food to which children had some antipathy, it would be 

 negative — in other words, it would arouse inhibition. In the case of a 

 group, against a group, the external induction would be enhanced. More 

 details must await further investigation. 



DISCUSSION AND SUMMARY 



Parotid saliva can be measured accurately by a suction cup or the use of 

 tampon. In human beings (adults of both sexes aged 18-25 and children 

 aged 9-11) we can detect the existence of natural conditioned reflex, in 

 everyday food. A weaker stimulant in unconditioned sahva, is not 

 maintained, but as for a stronger one in unconditioned stimulation, a 

 natural conditioned salivary reflex can be detected every time. 



Another more noticeable fact is, that if one uses the natural conditioned 

 stimulus, for instance, the sight of a pickled plum by a Japanese certainly 

 arouses conditioned saliva, but the sight of a pickled plum eaten by some 

 other man shows more abundant saliva. This phenomenon is called for 

 the time being " external induction " of the human natural conditioned 

 reflex. 



If the number of persons eating food was greater than the persons watch- 

 ing, the external induction increased in one ratio and decreased in another 

 ratio, which would show interaction of people in amass. 



REFERENCES 



Hayashi, T. and Suhara, R. 1962. Mechanism of secretion of resting saliva in men. 



Presented in this conference. 

 Kerr, A, C. 1961. Salivary Secretions in Man, vi. 86. Pergamon Press, London and 



New York. 

 Lashley, K. S. 1916. Reflex secretion of the human parotid gland. /. Exp. Psvchol. 1, 



461-493. 

 PoTH, E. J. 1938. A simplified technique for quantitative collections of salivary secretion 



of man. Proc. Soc. Exp. Biol. N. Y. 30, 977-8. 



